WP4 DESIGN GUIDE: GUIDE TO ENSURE GOOD...

WP4 DESIGN GUIDE: GUIDE TO ENSURE GOOD DESIGN PRACTICE FOR REPARABILITY”

Project nº 266222

Co-financed by European Commission

D4.1 – DESIGN GUIDE: GUIDE TO ENSURE GOOD DESIGN PRACTICE FOR REPARABILITY

Project Acronym: OPTIBODY

Project Full Title: “Optimized Structural components and add-ons to improve passive safety in new Electric Light Trucks and Vans (ELTVs)”

Grant Agreement No.: 266222

Responsible: CENTRO ZARAGOZA

Internal Quality Reviewer: MONDRAUTO

Version: 6 (2012.11.30)

Dissemination level: Public

SUMMARY:

The purpose of this document is the development of a design guide to ensure that OPTIBODY concept will have a good performance from the point of view of reparability and damageability while maintaining safety standards. This report is a first document that should be taken into account during the design phase of the OPTIBODY concept.

Recommendations included in this guide have been given based on the analysis of today’s vehicles’ architecture and taking into account the special characteristics associated to electric vehicles.

Based on the experience of Centro Zaragoza as member of RCAR, a first approach analyzes both general aspects and different parts of vehicle architecture regarding reparability. A second approach, based on the results of RCAR tests, has been done in order to know the most frequently damaged parts and the costs for vehicles with some similar characteristics to OPTIBODY concept.

At the end, as a result of the analysis, this report concludes with some recommendations to improve reparability and damageability in the OPTIBODY concept.

WP 4 DESIGN GUIDE: GUIDE TO ENSURE GOOD DESIGN PRACTICE FOR REPARABILITY

Project nº 266222


Page 2 of 58

INDEX

SUMMARY: ......................................................................................................................................... 1

1. Objectives and scope of this document ....................................................................................... 5

2. Glossary ....................................................................................................................................... 6

3. Executive summary ..................................................................................................................... 8

4. General aspects related to damageability and reparability ........................................................ 11

4.1. Types of materials ........................................................................................................... 11

4.2. Joining methods .............................................................................................................. 11

4.3. Mechanical, electrical and trim ........................................................................................ 12

4.4. Paint ................................................................................................................................ 12

5. RCAR - Low Speed Crash Test: Damageability / reparability assessment. .............................. 13

5.1. Frontal impact (against rigid barrier) ............................................................................... 13

5.2. Rear impact (mobile barrier) ........................................................................................... 14

5.3. RCAR – Bumper test ...................................................................................................... 16

6. Main features for current vehicles .............................................................................................. 19

6.1. Chassis ............................................................................................................................... 19

6.2. Body on frame platform ...................................................................................................... 20

6.3. Vehicle body panels ........................................................................................................... 23

7. Damageability and reparability analysis: Results of RCAR crash tests in current vehicles ....... 30

7.1. Frontal impact assessment ................................................................................................. 30

7.2. Rear impact assessment .................................................................................................... 39

7.3. Results compilations ........................................................................................................... 47

7.4. Analysis of most damaged parts in RCAR test procedure ................................................. 50

8. Design guide to ensure good design practice for reparability .................................................... 55

9. Bibliography ............................................................................................................................... 58


Project nº 266222


Page 3 of 58

LIST OF FIGURES

Figure 5.1 RCAR low speed crash test v2.2- Front impact left-hand drive (LHD) description .......... 14

Figure 5.2 RCAR low speed crash test v2.2- Front impact right-hand drive (RHD) description ....... 14

Figure 5.3 RCAR low speed crash test v2.2 - Rear impact description ............................................ 15

Figure 5.4 RCAR low speed crash test v2.2 - Rear impact left-hand drive (LHD) description .......... 15

Figure 5.5 RCAR low speed crash test v2.2 – Mobile barrier description ......................................... 15

Figure 5.6 RCAR low speed crash test v2.2 – Measure points ........................................................ 16

Figure 5.7 RCAR Bumper test - Bumper barrier with cover absorber ............................................... 16

Figure 5.8 RCAR Bumper test - Full frontal impact ........................................................................... 18

Figure 5.9 RCAR Bumper test - Corner impact ................................................................................ 18

Figure 5.10 RCAR Bumper test – Energy absorber force deflection corridors – Perpendicular loading .............................................................................................................................................. 18

Figure 5.11 RCAR Bumper test – Energy absorber force deflection corridors – Eccentric loading .. 18

Figure 6.1 Steel chassis is constituted by various high strength steels ............................................ 19

Figure 6.2 Cabin and chassis are separate for the other in heavy trucks ......................................... 20

Figure 6.3 Rear cargo area and mechanical components rest on chassis frame platform ............... 21

Figure 6.4 Detail of front bumper reinforcement and crush can ........................................................ 22

Figure 6.5 Bumper reinforcement is prolonged at the corners with a steel crush can ...................... 22

Figure 6.6 Bumper reinforcement extends to the vehicle corners according to "RCAR bumper test" suggestions ....................................................................................................................................... 23

Figure 6.7 Chassis legs without crush can increase repair cost ....................................................... 24

Figure 6.8 Bumper chassis leg and cooling pack are enough separated by steel crush can ........... 24

Figure 6.9 Inner wing has been displaced backward to prevent damage ......................................... 25

Figure 6.10 Front panel (black), front inner wing (yellow) and front outer wing (green) joined by threaded fasteners ............................................................................................................................ 25

Figure 6.11 Passenger cell remains rigid after a front and/or rear crash .......................................... 26


Project nº 266222


Page 4 of 58

Figure 6.12 A-Post & B-Post are made by Ultra High Strength Steel ............................................... 27

Figure 6.13 Sill reinforcements are sectioned into several parts, improving sill repair ..................... 27

Figure 6.14 Service parts do not match and joins incorrectly ........................................................... 29

Figure 7.1 Detail of the deformation in the left area on the rear panel .............................................. 46

Figure 7.2 Detail of the electric motor in the PSA vehicle ................................................................. 49

Figure 7.3 Example of deformed hood in Seat Ibiza ......................................................................... 51

Figure 7.4 Detail the damage suffered in the left rear panel of Toyota Prius .................................... 53


Project nº 266222


Page 5 of 58

1. Objectives and scope of this document

This document D4.1 is part of OPTIBODY’s project WP4: “Reparability requirements via modularity and reverse logistics”.

To achieve its objectives WP4 is divided into three tasks:

Task 4.1: Reparability analysis.

Task 4.2: Modularity in design.

Task 4.3: Recycling and reverse logistics.

Deliverable D4.1 is the outcome of Task 4.1 and the main objective of this task is the development of a guide to assist the design phase of the project (WP5) giving the optimum features related to damageability and reparability based on current vehicles’ architecture.

Features given in this D4.1 are part of the requirements to be taken into account in WP5.

To achieve its objective, D4.1 has been divided in the following parts:

General overview of different aspects related to damageability and reparability.

Description of RCAR tests for damageability/reparability assessment.

Analysis of the main features of current vehicles regarding damageability/reparability, analyzing

their different parts and including the costs related to repair.

As a result of the previous analysis a guide to achieve a good performance in reparability based on current vehicle’s architecture is given, which is the final objective of this task.


Project nº 266222


Page 6 of 58

2. Glossary

Reparability: Possibility and ease of repair, firstly in the physical sense and secondly in terms of cost.

Damageability: Capacity of a vehicle to withstand the force of a collision.

RCAR: Research Council for Automobile Repairs.

Bumper: Horizontal bar fixed across the front or back of a motor vehicle to reduce damage in a collision

Crush box/crush can: Parts designed to transform energy into deformation. They are located at the end of the front/rear rails (chassis legs)

Body panel: The sheet that forms the outside body pieces.

Chassis: The rectangular, usually steel frame, supported on springs and attached to the axles, that holds the body and motor of an automotive vehicle.

Chassis leg (U.K.) / front-rear rail (USA): The longitudinal beam of a chassis located at the end of the front/rear frame.

Bonnet (U.K)/ Hood (USA): the cover over the part of a car where the engine is

Bracket: a piece of metal, wood or plastic, usually L-shaped, that is fastened to a wall and used to support something.

Welding: To join two pieces of metal together by raising the area to be joined to a point hot enough for the two sections to melt and flow together. Additional metal is usually added by melting small drops from the end of a metal rod while the welding is in progress.

Curing time: The time required at a reference temperature for a compound to reach optimum physical properties

Rivet: A headed metal fastener of some malleable material used to join parts, as metal plates, of structures and machines by inserting the shank through a hole in each piece and forming a head on the headless end

Staples: A staple is a type of two-pronged fastener, usually metal, used for joining or binding materials together.

Threaded fastener: A discrete piece of hardware that has internal or external screw threads. They are usually used for the assembly of multiple parts and facilitate disassembly

Curb weight: The weight of a vehicle with standard equipment but without passengers or payload, but including all fluids (oil, full tank of fuel, coolant) and air conditioning (if equipped)


Project nº 266222


Page 7 of 58

Underbody: The underside of a car. Commonly called the floor pan. Usually made up of several smaller panels joined together to form a single unit and reinforced on the underside by floor pan cross bars.

Fender (USA)/ wing (U.K): Body section on the sides, covering the front and the rear wheels

Bodywork: The complete body structure mounted on the chassis of a vehicle with a separate chassis, and the complete sheet metal panel for unibody vehicles.

Frame: structural load-carrying members of a vehicle that support the engine and body and are in turn supported by the wheels of the vehicle.

Mount: A support for attaching something

Suspension strut tower: A sheet metal panel surrounding the upper mount of the suspension at the side panels of the engine compartment

Spot welding: A type of resistance welding in which two pieces of metal are joined at a series of points (spots) by means of heat (usually electrically generated) and pressure; the most important welding method in auto body construction

Front panel: A panel joining the front fender and forming a support for the headlights, grille, and bumper.

A-post: the post that is attached to the windshield and supports the roof

B-post: The post that connects the sills and provides roof support.

Sill: A longitudinal box-section member of the body shell at floor level, located below the doors.

Boot floor: The floor of the storage compartment of a vehicle

Rear panel: The panel of the body set underneath the boot lid

Tailgate: The door at the back.

Cluster lights: A group of lights at the rear corners of a vehicle, commonly comprising tail lamp, brake lamp, back-up lamp, rear fog lamp, reflector, and signal light.

Wheel arch: The edge of the fender around the wheel

Grille: A grating or crosswork of bars usually as an ornamental cover of the radiator which allows air to cool the engine.


Project nº 266222


Page 8 of 58

3. Executive summary

Damageability aims to prevent these elements to be affected in a crash, or at least to reduce as far as possible the number of items damaged by the impact. It aims to improve the performance of electric vehicles against these risks, reducing the crash effect in the final repair cost.

Moreover, the concept of reparability aims to ensure that if the damage has occurred, it will be easily repairable or replaceable. This report aims to provide the guidelines and some recommendations to be followed in the design of the OPTIBODY prototype in order to improve its performance if it has to be repaired.

The introduction of these concepts aims to reduce the low speed collisions cost, which ratio represents a high percentage of accidents, especially in urban environments. Although the ratio of injuries and deaths in collisions at low speed is lower than the ratio in high speed collisions, it represents a high cost for insurance companies and users in general.

The work package 4 analyzes the reparability of the new structure designed for the prototype developed by the OPTIBODY CONSORTIUM.

In the first part of this deliverable, it has been analyzed the main features related to damageability and reparability. Different manufacture materials influence not only its mechanical properties, but also those features related to the repair. Depending on the manufacture material, the repair will be different. Furthermore, the shape has also a great influence on the repair. During the repair, access to both sides of the damaged area is essential. A proper result requires access to both sides, in order to provide the damaged area with the same mechanical properties it had before the damage.

The next part of this deliverable is focused on the insurance crash test description. RCAR procedures are standardized and they assess the reparability and the damageability. Besides, RCAR has a less severe test focused on the bumper performance. “RCAR bumper test procedures” present the guidelines for the manufacturers to produce efficient bumper systems. RCAR makes suggestions about the incorporation of the high energy absorption beams and crush boxes, which have to be adjusted to the height of common damage, where they effectively protect in low-speed collisions.

The third part of this deliverable 4.1 sets a guideline focused on an analysis of the different chassis configurations and different body panels for vehicles currently available in the market. Subsequently, it pays special attention to the models related to commercial use and those whose configuration is similar to the prototype that OPTIBODY CONSORTIUM plans to develop. It has also been studied the reparability of the most common types of chassis, the self-supporting body, predominantly in passenger cars.

Over recent years protections to improve the reparability and damageability of conventional vehicles have been increased, evolving and modifying several elements like chassis legs, crossbeam, hood and bumper. It has been successfully added areas designed to transform the energy absorbed in the collision in permanent deformation.

The fourth part is focused on several reports about vehicles that share some features with OPTIBODY concept: hybrid and electric vehicles, commercial vehicles and light weight vehicles. All vehicles have been analyzed in the different standardized impact tests carried out by the RCAR,


Project nº 266222


Page 9 of 58

according to the procedure explained in the third part of this deliverable. During these tests, it has been observed the damaged elements in each one of the examined vehicles so that they must be taken into account in the design phase, especially in electrical system positioning.

After analyzing all the affected components, the decision about replacing or repairing such components is made, depending on the severity of the damage and the component functionality. In fact, there are parts which, due to their design or because their role is focused on passengers safety, are not allowed to be repaired. Other parts, however, are repaired using the most appropriate technique to the material and the damage extension.

The cost of reparation is determined by the cost of replacements, the labour cost for assembling, disassembling and repairing the damage, and later the cost for the paint labours. Reparability tries to reduce the extra costs due to these operations.

Finally, the last part of the document includes the main conclusions of the report, being considered the “Design guide to ensure good design practice for reparability” the main goal of this task, including as main recommendations:

Front and rear bumper have a high rate of damageability, forcing them to be repaired or replaced in most crashes. It is therefore a part that receives the first damage, so lightweight materials are being used due to the ability they have to recover shape easily. Design must be optimum according to reparability, and it is necessary to promote the use of threaded joints, rivets or staples instead of welds

Absorbers (crush cans) are essential to achieve good management of the energy generated in the collision. They may be closely joined to crossbeams or independent. Its mission is to act as a fuse at the ends of rails of the vehicle, progressively deforming according to the magnitude of impact.

The rear panel is the most vulnerable part in vehicle rear impacts and many elements such as tailgate, rear bumper and clusters lights are anchored to the rear panel. It is composed of several sheets joined and overlapped in some areas that hinder the independent removal of each one. It should contain the minimum number of elements directly attached to it for decrease the repair time consuming.

It is recommended to move bonnet rearward, increasing the size of the bumper in order to suffer less damage in low speed impacts.

If the cabin is considered independent and replaceable as a whole module, then it is appropriate that the union to chassis was bolted. For example with silent blocks. It isolated noise and vibration into the cabin. In turn, complete replacement is possible without spending excessive time. Silent blocks joints have a long tradition in automobile and truck manufacture, especially in suspension and engine brackets. In addition, some light trucks and pickups join the cabin over the chassis with silent blocks.

With the aim of avoiding the complex complete replacement of the frame, it is recommended that the chassis legs have a number of sectional areas where proceed to a partial replacement of non-recoverable parts is possible. In partial replacement the location of mechanical systems (brakes, suspension, steering, etc.) has to be taken into account, since they are anchored to the repaired area. Absorber boxes are installed easily and quickly, requiring little time for replacement. Installation must keep in account characteristics of


Project nº 266222


Page 10 of 58

accessibility, material composition, welding features (if possible) and corrosion protection recommendations to avoid damaging to rest of the elements.

If for weight consideration the chassis legs are made of aluminium. Absorption systems should withstand the efforts without transmitting energy to the chassis legs, at least in low speed collisions (e.g. 15 km/h RCAR test). Aluminium repair is more complicated than steel.

Electric components location, as a converter, inverter or charging port, must take into account the potentially most damages places. Damageability report shows the increase in the final cost when structural elements with an important task in safety and stability are broken (Renault Twingo II). Similarly, it happens with electrical components, if these components are not properly protected, its replacement will be more expensive.

Throughout different reports carried out, especially in electric and hybrid vehicles (Citroën C-Zero and Toyota Prius), none of the electrical system has been affected after undergoing to RCAR procedure. In both cases, the damage has affected only the body and chassis. High voltage batteries located at the rear axle remain intact. There is no electrical, magnetic or chemical risk after the impact.


Project nº 266222


Page 11 of 58

4. General aspects related to damageability and reparability

Optimum features in damageability and reparability benefit automobile manufacturers because they will have a competitive vehicle, highly appreciated by consumers, who will buy a vehicle with low maintenance and insurance costs, and also benefit insurers and repair industry since they will be able to carry out the repairs needed with no complexity.

The general aspects regarding reparability are divided into four subjects (more or less differentiated from each other):

Types of material Joining methods Mechanical, electrical and trim Paint

4.1. Types of materials

Many different materials are used to manufacture a vehicle. Basically the materials that should be repaired are metallic, polymers and composite materials.

Steel and aluminium are the most common metallic materials used in vehicles. Steel is usually used to build the chassis of the vehicle, especial at the places where a higher strength is required to guarantee passengers’ safety. The use of aluminium allows to decrease vehicles’ mass and it is an alternative to steel since aluminium has a higher resistance to corrosion. Aluminium repair is more difficult than steel, and therefore it will have higher service costs.

Nowadays, plastics represent an important percentage in vehicle’s architecture materials. The use of both types of plastic, thermoplastic and thermosetting is being increased. Ease to be manufactured, light weight, huge variety and lower prices make this material suitable for a wide range of applications like outer panels, brackets, trim panels, etc.

Composites represent an innovation in research and development of new materials in automobile manufacture. They are composed of two or more materials whose objective is to acquire some properties that they did not have separately. In automobile manufacture, the most common composite used is carbon fibber. This material presents interesting characteristics in durability, weight and strength but it is rarely used in external panels where any damage will be shown. Fiberglass is an enhanced material used in external panels for quadricycles. The features of lightness and malleability make composites have a relevant importance in the manufacture of quadricycles.

4.2. Joining methods

Joining methods are divided depending on their function, if it is necessary to provide extra material or not and if it is necessary to join with or without heat. Welding represents the most common joining method in the automotive industry but the introduction of new materials is replacing welding by


Project nº 266222


Page 12 of 58

adhesive joints. In order to facilitate the repair tasks, manufacture should not use permanent joints in elements commonly repaired. In this case, recoverable unions are recommended.

Manufacturers tend to use adhesive for both structural and non-structural joints. Adhesives allow the joint of lightweight materials, making them ideal for light duty vehicles. The main disadvantages are that the union requires a curing time and has worse mechanical properties, so that these aspects must be considered in repair and the use of adhesives should be therefore restricted. Nowadays, there is a wide range of products which provide a wide range of solutions in order to choose the most appropriate one for every case.

4.3. Mechanical, electrical and trim

Repair of a vehicle do not only focuses on the body, but also the mechanical parts, electrical components or trim of the vehicle should be repaired, and costs can be even greater than the repair of the body. Mechanical systems include the steering column, engine power, brakes, etc. Electrical systems are composed of wiring, CPU, wiper motors, lights and even airbags. Finally, trims refer to all elements whose purpose is more focused in the aesthetic appearance than in the functional aspects.

Joints without heat supply are widely used in automotive industry. Rivets, staples and screws are commonly used to attach many parts in the vehicle. Rivets are used in fixed parts which are impossible to be repaired and it is necessary to replace them. On the other hand, threaded fasteners are used on the mechanical components or panels most frequently repaired. This type of joint is the best for reparability, due to low time consuming and low-skilled tools required.

4.4. Paint

Paint gives the vehicle's final appearance and it involves more than just adding a colour to a body. It also contains all the base layers - the protective coatings and pre-treatments. During manufacture, these layers are applied by automatic systems, using paint robots and large ovens. While repairing automatic process are restricted and the painting process will be manually done by different operators and in different conditions. While in manufacture the entire vehicle is painted, in repair only damaged parts are treated with all the trims parts mounted so this restricts the way the paint is applied Not only the visible parts are painted, but also non-visible parts are coated by protective paint layers against harmful elements.


Project nº 266222


Page 13 of 58

5. RCAR - Low Speed Crash Test: Damageability / reparability assessment.

RCAR (Research Council for Automobile Repairs) crash tests detail the minimum procedures required to carry out low speed 15 km/h offset insurance crash tests in order to assess the vehicle performance from a damageability and reparability point of view.

The procedures are applicable to passenger vehicles with a maximum mass of 2500 kg (although in the later version of 2006, the mass was increased to 3500 kg, equivalent to the European classification M1). However, if any other vehicle requires performing the tests, they could be applied by the manufacturer or a specialized centre.

RCAR procedures have had some changes during several versions, which include a change in the vehicle orientation, from 0 degree to 10 degree respect to the vehicle longitudinal axis. Also, rear impact mobile barrier had some modifications, mainly in barrier mass, which changed from 1000 to 1400 kg in all the tests made since 2006.

RCAR tests characteristics are summarized below.

5.1. Frontal impact (against rigid barrier)

The barrier should remain fixed after the test, therefore it must be secured to a rigid weight or anchored directly to the floor. The front part should be completely vertical with a maximum deviation of ±1°.

The barrier front side has an orientation of 10° (±1°) relative to the perpendicular of the vehicle longitudinal axis, and will allow an overlap of 40% (±25mm. Figure 5.1 describes frontal impact specifications for left-hand drive, whereas for right-hand drive the barrier changes its orientation as shown in Figure 5.2.

The vehicle test weight will be the curb weight and will include a 75 +- 5 kg dummy or equivalent ballast anchored with a 3-point belt in the driver's seat (or the restraint system the vehicle has).

The test speed should be 15 +1 km/h measured not more than 1 meter before contact with the barrier..


Project nº 266222


Page 14 of 58

Figure 5.1 RCAR low speed crash test v2.2- Front impact left-hand drive (LHD) description

Figure 5.2 RCAR low speed crash test v2.2- Front impact right-hand drive (RHD) description

5.2. Rear impact (mobile barrier)

In the rear impact test, the vehicle is struck by a mobile barrier.

The mobile barrier shall have a mass of 1400 ±5 kg with the dimensions shown in Figure 5.3, Figure 5.4 and Figure 5.5. The front part is completely vertical with a maximum deviation of ±1°.

Just like the frontal impact, test is performed with a 40% (± 25mm) overlap and an orientation of 10° ±1º respect to the vehicle longitudinal axis. The overlap is measured at the point of initial impact by projecting the inboard edge of the barrier in the mobile barrier longitudinal axis onto the test vehicle rear end.

In order to avoid more than one impact which could alter the results, the barrier is provided with brakes or restraint systems.

Test speed should be 15 +1 km/h measured not more than 1 meter before contact with the vehicle.

.


Project nº 266222


Page 15 of 58

Figure 5.5 RCAR low speed crash test v2.2 – Mobile barrier description

Measurements, inspections and observations

In order to determine the deformations produced in the test variations in the measurements before and after the impact should be taken for both the external body and the under body (see suggested forms in figure 5.6).

Marks for high speed film analysis will be placed in 200mm intervals along the length of the vehicle and other important areas according to manufacturer's or test house requirements. Doors opening should also be marked in order to detect any movement during the impact.

Tests must be completely documented, including a video recorded with high-speed cameras. Also, the vehicle is photographed after the tests to assess the damage percentage on the vehicle allowing to compare it with other models in different markets.

Figure 5.3 RCAR low speed crash test v2.2 - Rear impact description

Figure 5.4 RCAR low speed crash test v2.2 - Rear impact left-hand drive (LHD) description


Project nº 266222


Page 16 of 58

Figure 5.6 RCAR low speed crash test v2.2 – Measure points

5.3. RCAR – Bumper test

The RCAR bumper test arises as a complement to "RCAR Low speed crash test" focusing mainly on the specifics features that vehicle bumpers should have.

In the bumper test procedure, RCAR encourages manufacturers to produce bumpers with effective energy absorption systems, including absorber beams and crush cans to protect the vehicle in low speed crashes. Place absorption systems at the right height, prevents overriding or underriding, which are responsible for a significant increase in repair costs. Car to car impacts have a high cost, affecting a large number of elements, mainly due to the incompatibility between vehicles and / or low strength of the bumpers and absorbers. In case of impact against bigger vehicles, such as pickups, SUVs, etc., there is a trend to produce overriding, given the difference in height between absorber beams.

Figure 5.7 RCAR Bumper test - Bumper barrier with cover absorber

RCAR bumper procedure is focused on the three fundamental aspects observed in the accident statistics:

Stability: Increase the section height of the bumper, avoiding a difference in height between the bumpers of the vehicles collided, regardless of vehicle type, load status or braking.


Project nº 266222


Page 17 of 58

Geometry: Place the bumper at the right height to ensure compatibility with other vehicles, extending the bumpers laterally to the corners.

Energy absorption: The bumper must absorb the energy in low speed impacts, protecting any other part of the structure.

The procedure for the bumper test is explained below.

Barrier dimensions

The bumper barrier is composed by a rigid steel structure (built with a radius of 3400 mm and a width of 1500 mm ± 25 mm across its full width and with a flat vertical face of 100 mm ± 2 mm) and a backstop fixed on the top of the barrier (constructed from a steel plate, 200 mm tall and at least 8 mm thick) with the same radius and width as the bumper barrier face.

The barrier is completed with a deformable absorber along the barrier of 50mm depth made of aluminium honeycomb, egg-crate aluminium or thermoplastic. The deformable absorber is covered by a plastic reinforcement which completes the crush strength of the bumper barrier. The crush strength for materials used in the absorber should range between the corridors shown in Figure 5.10 and Figure 5.11.

Vehicle conditions

The vehicle to be tested should be at the vehicle manufacturer’s nominal curb weight, including fuel tank filled at least 90% of capacity. The test weight includes a 75 kg±5 kg test dummy or equivalent weight on the driver’s seat, secured with a standard 3-point seat belt.

A few meters before the crash, the vehicle should be free of any external forces that could alter the test results. At the moment of impact, it also has to have all the ignition systems switched on, turned in on position (position 2) and safety systems on (airbag and seat belt pretensioners).

Full width test

The vehicle must be aligned with the bumper barrier and the maximum lateral deviation allowed is ±50 mm.

The barrier ground clearance shall be 455 ±3 mm for frontal impact and 405 or 455 ±3 mm (depending on the local market) for rear test.

The impact speed shall be 10 ±0.5 km/.

Corner test

A high percentage of accidents involves the impact in the corners of the vehicle with serious consequences on the structure of the vehicle due to a lot of vehicle models do not having corner bumper reinforcements. In case of an impact in this area, the headlights and fenders are unprotected.


Project nº 266222


Page 18 of 58

The corner test is performed at a speed of 5 km/h against a rigid barrier positioned with a ground clearance of 405 or 455 ±3 mm, depending on the local market.

In this test the vehicle shall overlap the lateral edge of the barrier by 15% of the vehicle width (Figure 5.9 shows a schematic drawing of corner impact).

Figure 5.8 RCAR Bumper test - Full frontal impact

Figure 5.9 RCAR Bumper test - Corner impact

Figure 5.10 RCAR Bumper test – Energy absorber force deflection corridors – Perpendicular loading

Figure 5.11 RCAR Bumper test – Energy absorber force deflection corridors – Eccentric loading


Project nº 266222


Page 19 of 58

6. Main features for current vehicles

Different features for current vehicles regarding damageability and reparability are described below:

6.1. Chassis

The chassis is the structural element responsible for supporting the dynamic and static efforts of the vehicle, providing rigidity and shape. There are three types of configurations: separate chassis and body, body with platform-chassis and self-supporting body.

Separate chassis and body is the oldest configuration used in the cars and was one of the most used until 1990’s, but currently it is only used in heavy vehicles (trucks, buses, etc.), cars with fibber body and competition models. Nowadays this system has been discarded due to the significant increase in price and in vehicle weight that increases the height of the centre of gravity with the corresponding decrease in stability and aerodynamics.

Body with platform–chassis is used in cars that usually have to withstand high loads and efforts. This is a construction commonly used in vans, trucks, pickups and vehicles designed to travel on the paths. Body-platform configuration allows a huge range of different bodies mounted on the same base platform.

Last system (self-supporting body) is based on the idea of making a sturdy box that in turn is self-supporting, with different mechanical and decorative elements attached to it. This design is currently implemented by most vehicle manufacturers, in models and serial large volume of sales. This type of body is lighter, more stable and more rigid compared to other bodywork. They are more economical because series production involves lower costs and a better construction by the mechanization of the work.

Figure 6.1 Steel chassis is constituted by various high strength steels

The chassis must be correctly designed to absorb the impacts suffered by the vehicle anywhere and transmit them to the rest of the elements. This way it aims to achieve that its elements to be deformed, preventing that any effort is transmitted to the occupants. Energy absorbed by the


Project nº 266222


Page 20 of 58

chassis is transformed into a deformation of its parts which definitely will require being repaired or otherwise replaced.

6.2. Body on frame platform

The body over frame design is used in heavy vehicles for goods transport like heavy / medium / light trucks, pickups and vans. During long time, this configuration was frequently used in car manufacturing, but nowadays the development of light structures has made it is used only in vehicles for goods delivering.

The platform is constituted by a lightweight frame made up by the union of several sheets, forming a strong base and serving to support both the mechanical parts and subsequently the body. Brake systems, suspension, steering or power train are supported directly by the platform. The body can join the platform using screws or by welding. This production technique allows the manufacturer to offer its customers a range of different bodies mounted on the same base platform, resulting in a more efficient manufacturing at lower cost.

The frame is optimised providing maximum rigidity and strength to achieve good features in energy absorption.

Figure 6.2 Cabin and chassis are separate for the other in heavy trucks

The design must take into account some considerations in both frontal a rear structures, in order to achieve a proper behaviour regarding reparability and preventing excessive damage that lead to its complete replacement. The stiffness and strength is increased in some areas while others are specially designed to absorb energy, like crash cans placed in front/rear of the rails, or even programmed and controlled deformation rails. In severe crashes, a part of energy cannot be


Project nº 266222


Page 21 of 58

transformed into a deformation, so it is transferred to the passenger compartment, which has to be specially designed to minimize potential injuries on the passengers.

The frame is the largest item in the chassis, and subsequently an expensive repair component when damaged, requiring in some cases a full replacement. A lack of limitation in damages will increase the cost if during the design phase it has not been taken into account any consideration in front/rear rails, beams, mounts or brackets. Availability and accessibility for these parts reduces greatly the repair time and finally the cost. Any consideration must be complemented by appropriate instructions and availability of service parts that fit the needs and requirements.

Along the chassis, there are several reference and measure points in order to correct adequately any misalignment or defect and restore the structure to its pre-crash state. Those reference points should be easily accessible without difficulties that could complicate the recovery work. The manufacturer provides the necessary information about positioning these points in any of the three dimensional axes. In order to return the structure back to its initial state, appropriate tools must be used depending on the material and physical limits. For example, for chassis made of steel, heat supply to repair is allowed.

Replacement service parts (brakes, steering, suspension or power system), including their availability, and intervention procedures should be documented and explained by the manufacturer and provided to workshops.

Figure 6.3 Rear cargo area and mechanical components rest on chassis frame platform

With the aim of avoid the complex complete replacement of the frame, it is recommended that chassis beams have different sectional areas, allowing a partial replacement of non-recoverable parts. In partial replacement, it has to be taken into account the location of mechanical systems (brakes, suspension, steering, etc.) that are anchored to the repaired area. Absorber boxes should be installed easily and quickly, requiring little time for replacement. Installation must take into account characteristics regarding material composition, welding features (if possible) and corrosion protection recommendations to avoid damages to rest of the elements.

Areas designed for absorption of energy are also the weakest and therefore, these areas are the ones where structure is going to collapse. They are located at the ends of rails where access is carried quickly, without needing to remove a great number of components becoming a quicker and efficient process. In addition, these absorption areas prevent the spread of the damage to inaccessible and hard to repair areas.


Project nº 266222


Page 22 of 58

Crush cans have some holes, slots, grooves or points which allow to collapse according to the impact level and the amount of energy absorbed.

Figure 6.4 Detail of front bumper reinforcement and crush can

In body-on frame platforms metal bumpers mounted on brackets or a plastic bumper with metal reinforcement are primarily being used, while the last one is the most common configuration in passenger cars or light commercial vehicles.

The RCAR bumper test at low speed presents the guidelines to produce effective impact absorbing systems by adjusting height, width and material of rails and crush cans that protect the vehicle at low speed impacts. Cross beams are placed in a way that prevent override or underride leading the chassis to be seriously damaged. If these elements are properly placed, the damage will only affect to minor items that are prepared for that. Recommendations advise to include crush cans in the bumper reinforcement, making reinforcement manufacture process more complex and expensive, but preventing rails to be affected and, for this reason, most efficient in costs in long term.

The RCAR bumper test procedure recommends that vehicle bumpers should prevent or limit as much as possible the damage sustained in these minor crashes. However, many vehicles do not have bumper reinforcement beams that extend laterally beyond the frame rails, leaving expensive vehicle components such as headlamps and fenders unprotected. Impacts at low-speed over corners (RCAR corner test is done at 5 km/h) represent a serious damage on sides of the vehicle if they are not enough protected. Therefore it is very appropriate to extend the bumper reinforcement to those corners.

Figure 6.5 Bumper reinforcement is prolonged at the corners with a steel crush can


Project nº 266222


Page 23 of 58

The body is mounted over the frame designed to withstand the elements such as brakes, steering, engine, suspension, etc. Brackets are welded to the chassis during the manufacturing phase, where automated robots are used to weld under proper conditions and specific parameters. While repairing, some of these mounts and brackets will be removed so the operator must be aware of restrictions during welding repair so documentation about removal and replacement of brackets should be provided in a guide that includes welding parameters, intensity, material, distance between wire filler and plate, etc.

6.3. Vehicle body panels

External body panels represent the most potential damage zone. Panels are responsible of final aerodynamic and aesthetic in the vehicle and they usually do not have structural functions. External body panels are designed with lightweight materials, which must be assembled / disassembled easily to improve reparability or replacement procedures. Depending on location in the vehicle, different material are used, for example bumpers are made of plastics (PP + EPDM, PC), while the hood is usually made of metallic sheet (aluminium or steel). Composites are becoming a real option for exterior panels, due to good features for lightness and adaptability to the required shape.

Front and rear bumpers have a high rate of damageability, forcing them to be repaired or replaced in most crashes. It is therefore a part that receives the first damage, so lightweight materials are being used as the ability they have to recover their shape easily. Design must be optimum according to reparability, and it is necessary to promote the use of threaded joints, rivets or staples instead of welds. Grids, sensors and logos are frequently replaced; despite they do not suffer any damage, because they are joined by fixed welds. Union of these parts with the bumper affects the time and cost of repair / replacement, being important that if they are not damaged, they can be recovered.

Bumper reinforcement is an energy absorber part on the vehicle in a frontal or rear crash at low speed. It carries the bumper cover and joins the front ends with the chassis rails through the crush cans. Bumpers must be on both front and rear of the vehicle and they have to be replaced without cutting or welding. Raising bumper’s height over the 100 mm will avoid the excessive damage when override or underride occurs. It must be sufficiently stable to support the efforts during central and eccentric impact. Keeping an appropriate distance between bumper beam and any parts behind it will avoid intrusion of the reinforcement when it is deformed.

Figure 6.6 Bumper reinforcement extends to the vehicle corners according to "RCAR bumper test" suggestions


Project nº 266222


Page 24 of 58

Crush cans are fitted on the edge of the chassis rails absorbing energy in low speed impacts and avoiding structural damage on rails. They are made of different materials depending on the requirements, but are mainly of steel or aluminium, which can greatly deform instead of break down, and they are joined by screws, which facilitates their replacement in case of impact.

Crush cans are relatively new elements in the architecture, whose introduction has reduced reparability costs.

Figure 6.7 Chassis legs without crush can increase repair cost

Figure 6.8 Bumper chassis leg and cooling pack are enough separated by steel crush can

The front inner wing is joined to the suspension strut tower and chassis rails, being one of the most damaged parts in case of front impact. High percentage of damage makes it susceptible to be frequently repaired / replaced and for this reason, designers have chosen a new design where it is fitted as far back as possible to avoid being damaged. In addition, the introduction of natural joints decreases repair times because the operator do not have to create a joint and remove any evidence of damage.

For the last 5-10 years, front inner wing and suspension strut tower were joined. This involves that in frontal impacts the whole part had to be replaced, in spite of the fact that suspension strut was not damaged. Nowadays, manufacturers separate them in two parts, joining them by spot welding. This option allows replacing one of them individually, reducing the time consumed and the final cost.

In most cases, front inner wing, outer wing and suspension strut tower are supported by the front panel reinforcement. When the reinforcement is damaged in the front part of the reinforcement, a section can be made to replace the damaged part. Replacement of the whole reinforcement is time consuming and it is only carried out when there is substantial damage.


Project nº 266222


Page 25 of 58

Figure 6.9 Inner wing has been displaced backward to prevent damage

The front outer wing is joined to the front inner wing and the front panel reinforcement by threaded joints instead of rear outer wing which are welded. The outer wing suffers important damages in corner collisions, especially if the bumper has no side reinforcements to absorb energy. The outer wings are made by lightweight materials which should recover the original form in slight impacts. When important damage happened, an analysis to evaluate the best form to repair the wing or even remove it is necessary.

The front panel is fitted to the chassis legs, supplying a support to both outer wings and hood. The front panel has a high accident rate, which has leaded to a material change in the manufacturing and joining method, becoming screwed rather than welded. It is not recommended to install the front panel on the bumper, crush can or the area of the chassis leg that will not be affected in case of a crash at low speed. Also the front panel´s material has changed replacing metal by plastic, and even composite.

Figure 6.10 Front panel (black), front inner wing (yellow) and front outer wing (green) joined by threaded fasteners


Project nº 266222


Page 26 of 58

Over the years, the bonnet has changed its simply aesthetic functionality to work for the protection of pedestrians. In case of accident, the pedestrian's head impacts the bonnet, causing injuries of diverse consideration, so that protection of pedestrian has changed the layout and materials on the hood. The double hood design protects the pedestrian’s head to hit hard areas, but this safety requirement makes the bonnet more difficult to be repaired, due to limited access to both joints. Central reinforcement inside the hood has disappeared, therefore any damage on it is bigger, forcing in most cases to replace it.

Bonnets are becoming replaced elements instead of repairable elements. The RCAR low speed test and the RCAR bumper test protocol recommend moving the bonnet rearward and increasing the size of the bumper in order to suffer less damage in low speed impacts.

The front chassis leg has been reduced in lngth? due to the introduction of the crush can; even so, the task of this item is to absorb energy in severe crashes. In case of low speed impacts, crush cans should absorb all the energy, avoiding the chassis leg to be damaged. In high speed impacts, when the vehicle cannot be repaired, the chassis legs transform energy in a permanent deformation, so it is important if they have points specially designed to pre-deform, allowing to be replaced partially. In this way, costs and time associated with vehicle repair are considerably reduced.

To protect the lower parts of the vehicle from damage, as well as any possible underrun, some vehicles are fitted with under trays. This non-structural element is fitted by rivets or staples to the bumper or front panels, requiring the complete replacement in case of collision.

The cabin or passengers’ compartment represents the most important part in the vehicle regarding safety. It should have enough strength to reduce any risk of occupant injuries. The cabin must resist roll over and side impacts, avoiding an intrusion of any element which could injure driver or occupants. It is divided in several parts which will be described below.

Figure 6.11 Passenger cell remains rigid after a front and/or rear crash

A-post and B-post

Normally, A-post and B-post are made of high strength steel, but ultra high strength steel reinforcements are indispensable to reinforce the body side pillars. It makes a rigid structure to resist collision efforts and minimize occupant injuries. Due to its excessive rigidity and its complexity, usually it is partially replaced instead of completely repaired.


Project nº 266222


Page 27 of 58

Figure 6.12 A-Post & B-Post are made by Ultra High Strength Steel

B-post and sill are joined and, during the repair one part indirectly will affect the other, so overlap reinforcements are indispensable to improve reparability. Ultra High Strength Steel used in B-Post reinforcement does not allow being sectioned and then welded. For this reason, a complete replacement is required. To facilitate replacement, UHSS reinforcement’s size has been reduced, allowing a better repair procedure of the B-post.

Sill

The sill is located in the lower part of the cabin, where A-Post and B-Post are welded by automatic robots in manufacture. The sill reinforcement is divided in different parts, minimizing time consuming in repair when the damage is located in a specific zone.

Figure 6.13 Sill reinforcements are sectioned into several parts, improving sill repair

Doors

Apparently doors are not part of the structure of the vehicle, but this is wrong because they have a great influence in side impacts. Door reinforcements are made by Ultra High Strength Steel giving rigidity and guarantying the stiffness of the area to prevent the introduction of any element inside the passengers’ compartment. The side impact energy is absorbed by A-Post, B-Post and the doors.


Project nº 266222


Page 28 of 58

They must be rigid enough to protect the vehicle’s occupants, transferring efforts to the longitudinal axis and avoiding an excessive deformation and introduction of elements inside the cabin. The doors are therefore parts that protect the driver and occupants, but they are frequently damaged in side impacts at low speed. The simplest door, the easiest to repair, and therefore its cost decreases considerably.

Currently there are no standard side impact tests at low speed to assess damage on vehicle side as in bumpers and front/rear low-speed collisions.

Doors are usually made of 0.7 mm thick steel sheet covered with a layer of paint. To design separate zones of different repairing complexity will reduce operating times and final costs. The door hinge bolts have to be inserted from inside the body shell, so access should be available by using easily removable trim panels. Shape of door skin makes the replacement more difficult due to the complex shape around the windows. The window frame increases the cost of repair, from the point of view of reparability; doors that do not have it are easier to be repaired.

Doors have a large amount of electrical components which must be anchored to the inner frame. Good access should be available, so it can be properly worked. In the same way, to have separate access covers in the door trim for the removal and adjustment of the window, without needing to remove the door trim completely, will reduce labour times.

Roof

The Vehicle’s roof is supported on the vehicle sides, extending from the windshield to the rear window. It consists of a large area that covers and protects the passenger compartment against rollover. Some vehicles have folding roof, which complicates the repair process due to its complexity and numerous mechanisms. Folding roofs reparability must be performed by qualified personnel with the right tools. When it is necessary to replace completely the roof; all hydraulic, electrical and mechanical items must be disconnected and removed from the roof.

Service parts

Service parts are usually available in separate body, which a priori is a good solution. However, this configuration presents problems due to irregularities and / or overlaps in some panels. During the repairing process, panels are frequently cut and if this is not done correctly it may produce mismatches in the joints. To homogenize the sides of the vehicle, providing the whole side, service parts price is equalized and joints can be better. Besides, it allows parts to be cut in affected areas and therefore properly proceed with the repair.


Project nº 266222


Page 29 of 58

Figure 6.14 Service parts do not match and joins incorrectly

Vehicle rear

The vehicle rear has similar characteristics to the frontal area, but is subjected to different efforts. Generally, rear rails do not support the engine, and it is designed for the carriage of goods. The boot floor is made of steel or plastic and is designed to withstand a spare wheel or equivalent and to load goods. It is supported by the rear chassis legs that transfer loads to the rest of the chassis. Size, location, thickness and material of the rear chassis legs are submitted to numerous studies to determine their suitability for each type of vehicle and its deformability.

The rear panel is the most vulnerable part in vehicle rear impacts. Many elements, such as tailgate, rear bumper and clusters lights, are anchored to the rear panel. It is composed of several sheets joined and overlapping in some areas that hinder the independent removal of each one. It should contain the minimum number of elements directly attached to it in order to decrease repair time consuming.

The front and the rear have the same needs to avoid damage in the occupants. Both zones have bumper and crush cans whose task it is to absorb impact energy. As in the front chassis legs, the rear chassis legs should have crush cans for low-speed impacts. The rear chassis legs are sandwiched between floor, wheel arch and other closing pieces. Separate panels make it easier to remove.

When the fuel filler neck is affected, the best option is full replacement. If the fuel deposit and the filler neck cannot be separated independently, repair becomes dangerous due to the direct contact between inflammable fuel and repair tools, usually with heat supply.


Project nº 266222


Page 30 of 58

7. Damageability and reparability analysis: Results of RCAR crash tests in current vehicles

In order to know the behaviour of current vehicles from the point of view of damageability and reparability, results of RCAR tests for different vehicles have been analyzed.

The OPTIBODY concept has been categorized as a L7e vehicle, which involves a vehicle with a limited unladen mass of 550 kg, excluding batteries, thought to deliver goods (or to do public services), and electric powered.

Vehicles that have been chosen for the analysis are those that, in more or less way, better suit to the chosen category, power or weight of OPTIBODY electric concept, in order to obtain a reference to be at least achieved by the OPTIBODY concept when it will be tested under RCAR procedures.

Electric vehicles are being gradually introduced in the market and only PSA platform has been assessed under RCAR tests. This platform corresponds to Citroen C-Zero, Peugeot Ion and Mitsubishi iMiEV electric models.

The analysis of current vehicles under RCAR tests will allow to establish a reference not only in the most frequently damaged parts (behaviour of the vehicle from a damageability point of view) but in terms of costs, a very important subject in reparability, as it is the way to compare a good/poor vehicle from a reparability point of view.

7.1. Frontal impact assessment

Vehicles have been tested in an impact against a rigid barrier at a speed of 15 km/h, as indicated by the procedure of RCAR. In the tests made before 2006, the vehicle impacted against the barrier along the longitudinal axis, while for vehicles tested after 2006, the impact angle changed to 10° respect to the perpendicular axis. The procedure for frontal impact is explained in section 5 of this deliverable.

Table 7.1 shows vehicles whose results to RCAR frontal test have been analyzed, including the electric model from PSA: Citroën C-Zero – Peugeot Ion – Mitsubishi iMiEV and the first hybrid vehicle in the market in 2004, Toyota Prius. Light passenger cars manufactured by different companies (Toyota iQ, Citroën C2 and Renault Twingo II) and commercial vehicles within the same scope that OPTIBODY electric concept (such as Peugeot Expert, Peugeot Partner and Citroen Berlingo) are included.


Project nº 266222


Page 31 of 58

Vehicle Mass Engine YearTest date

Test Number

Speed

Ford Fiesta 1113 kg 50 kW 2002 Sep-01 BLS 1 2817 15.30 km/h

Toyota Prius 1401 kg 57 kW 2004 Feb-03 - 15.65 km/h

Citroën C2 1031 kg 44 kW 2003 Apr-03 03F388 15.09 km/h

Volkswagen Fox 1060 kg 55 kW 2005 Oct-04 - 15.14 km/h

Toyota Aygo 885 kg 50 kW 2005 Nov-04 990N 15.25 km/h

Peugeot 1007 1236 kg 55 kW 2005 Dec-04 04F682 15.30 km/h

Chevrolet Kalos 1060 kg 69 kW 2005 Oct-05 - 15.06 km/h

Toyota Yaris 1063 kg 50 kW 2005 Jun-05 371L 15.24 km/h

Peugeot Expert 1814 kg 66 kW 2007 Oct-06 06F274 15.10 km/h

Renault Twingo II 1000 kg 43 kW 2007 Sep-07 - 15.10 km/h

Citroën Berlingo – Peugeot Partner

1541 kg 66 kW 2008 Oct-08 07F442 15.30 km/h

Seat Ibiza 1116 kg 63 kW 2008 Feb-08 080801ES 15.20 km/h

Toyota iQ 920 kg 50 kW 2009 Sep-08 630L 15.20 km/h

Audi A1 1115 kg 63 kW 2010 Feb-10 - 15.00 km/h

Citroën C-Zero – Peugeot Ion

1110 kg 35 kW 2010 Sep-10 B040870L 15.78 km/h

Toyota Yaris 1115 kg 51 kW 2012 Mar-11 - 15.13 km/h

Table 7.1 Vehicles whose results to RCAR frontal test have been analyzed.

Table 7.2 shows, on the first column, a photo detailing a general view of vehicle final state, after being submitted to the frontal test. On the second column, there are all the elements described that have been affected, regardless if they have been damaged or deformed.


Project nº 266222


Page 32 of 58

Reparability and damageability - Front impact

Ford Fiesta

Hood, front bumper, radiator grille, front crossbeam, front panel, left headlight, left radiator air channel, condenser, left chassis leg and hood hinges

Toyota Prius

Front bumper, crush can absorber, lateral and superior bumper brackets, crossbeam, bulb and socket fog lamp left, left lower headlight guard, hood, hood emblem, hood hinges, upper and lower left brackets radiator, hood lock, left chassis leg and left air channel radiator

Citroën C2


Project nº 266222


Page 33 of 58


Front bumper, crossbeam-absorber, grill, left headlight, grip plate absorber and left end of the chassis leg

Volkswagen Fox

Front bumper, front panel, front crossbeam, radiator, condenser, hood, left front headlight, and front left headlight

Toyota Aygo

Front bumper, bumper reinforcement, left bumper bracket, lower bumper bracket absorber, right radiator spoiler, front lower left plate, left front panel reinforcement and subset of the front reinforcement


Project nº 266222


Page 34 of 58

Reparability and damageability - Front impact Peugeot 1007

Front bumper, bumper molding, upper and lower bumper grill, bumper absorber, radiator grill, front crossbeam, condenser and left headlight

Chevrolet Kalos

Front bumper, front inner panel, license plate reinforcement, bumper bracket, hood, front grill, left and right headlight, front left fog lamp, air condition condenser, air condition tube, power steering tank, left front wing, left chassis leg, front left wheel arch and battery support

Toyota Yaris 2005

Front bumper, lower pedestrian absorber, front crossbeam, additional radiator support, left crossbeam absorber, left headlight, lateral radiator support and lower radiator crossbeam

Peugeot Expert


Project nº 266222


Page 35 of 58


Photo Non available

Front bumper, left bumper trim, bumper grille, upper and lower bumper beam, fan motor, left front wing bracket, closure sheet chassis leg, left headlight, front panel and left chassis leg.

Renault Twingo II

Front bumper, crush can absorbers, front crossbeam, left headlight, front panel, left chassis leg and battery bracket.

Citroën Berlingo - Peugeot Partner

Photo Non available

Front bumper, bumper reinforcement, pedestrian deflector, bumper trim, left headlight, left front wing, crossbeam bumper, upper chassis leg absorber, engine protection under tray, front panel, right and left chassis leg, left front door and right front wheel arch

Seat Ibiza

Front bumper, bumper spoiler, front crossbeam, left headlight, front panel, hood, fan CPU support and condenser

Toyota iQ


Project nº 266222


Page 36 of 58


Front bumper, guards, grids, front crossbeam, crush can absorbers, brackets, right and left headlights, support front facade, radiator enclosure, lower bracket to front bumper, battery bracket and battery

Audi A1

Photo non available

Left front bumper, central front bumper, front bumper support, bumper absorber, radiator grill, covers, hood, right and left hood hinges, left headlight, front left wheel arch covering, front panel, air channel and front sound-absorbing

Mitsubishi iMiEV – Citroën C-Zero – Peugeot Ion

Front bumper, bumper bracket, left crush can, air baffle, left fender, left headlamp, front driving axle, front bumper, left chassis leg extension, enclosure fan, radiator and air conditioning condenser

Toyota Yaris 2012

Front bumper, front bumper cover closure, front crossbeam, front bumper absorber, left crush can, radiator grill, radiator grill moulding, pin left headlight, hood, left hood hinge, left front wing and support, upper A-pillar covering, wheel arch, radiator supports, left radiator spoiler, left chassis legs ends plate and battery support

Table 7.2 Broken or damage components after front impact at 15 km/h in each vehicle


Project nº 266222


Page 37 of 58

Table 7.3 shows the repairing costs (updated to 2011, for the Spanish market, in Euros) of each model, both in materials and hours spent on repair. Service parts costs on electric models are considerably higher than in other vehicles with similar characteristics, since their parts have higher costs because they are new vehicles without unprecedented models.

The number of hours spent on repairing and painting of electric and hybrid models (more than 22) are higher than the number of hours for other models, more than twice that invested in some models of passenger cars such as Toyota iQ or commercial as Peugeot Expert. Renault Twingo II requires 3 hours less than hybrid or electric models, a time much higher than its similar scope models. However, some light passenger cars, such as Citroën C2, Toyota Aygo and Toyota Yaris´05, spent less than ten hours during the front repair.

The final assessment of frontal impact is obtained from service parts cost and hours spent in repair working. The higher cost in the front test is more than 3000 € for electric cars, double than conventional models. The Chevrolet Kalos has a high cost (more than 2831 €) due to the great number of elements affected, so the time consuming increases in the same proportion.


Project nº 266222


Page 38 of 58

Model Test date

Repair and paint cost

Bodywork and paint

(h)

Bodywork cost (€/h)

Front valuation

Ford Fiesta Sep-01

1614,18 13.10 39,6 2132,94

Toyota Prius Feb-03

1300,80 22.45 39,6 2189,82

Citroën C2 Apr-03 514,73 9.30 39,6 883,01

Volkswagen Fox Oct-04 1045,16 14.05 39,6 1601,54

Toyota Aygo Nov-04

456,01 8.70 39,6 800,53

Peugeot 1007 Dec-04

1172,08 12.70 39,6 1675,00

Chevrolet Kalos Oct-05 1950,24 22.25 39,6 2831,34

Toyota Yaris´05 Dec-05

375,16 8.60 39,6 715,72

Peugeot Expert Oct-06 1521,97 11.15 39,6 1963,51

Renault Twingo II

Sep-07

1276,96 19.05 39,6 2031,34

Peugeot Partner Feb-08

1137,17 14.45 39,6 1709,39

Citroën Berlingo Feb-08

1121,36 14.45 39,6 1693,58

Seat Ibiza Feb-08

1296,70 15.75 39,6 1920,40

Toyota iQ Sep-08

992,99 10.30 39,6 1400,87

Audi A1 Feb-10

1341,41 12.10 39,6 1820,57

Peugeot Ion Sep-10

2149,38 22.60 39,6 3044,34

Citroën C-Zero Sep-10

2192,17 22.60 39,6 3087,13

Toyota Yaris´12 Mar-11

1228,62 12.65 39,6 1729,56

Table 7.3 Frontal impact valuations


Project nº 266222


Page 39 of 58

Comparing the average front valuation for light passenger vehicles and for commercial vehicles, data show an average cost over 1790 € for commercial vehicles, versus 1250 € for light passenger cars.

Detailing the average cost of the parts and the hours spent on the repair, the data reflect lower costs and less hours spent on light passenger vehicles repair.

Model Test date

Repair and paint cost

Bodywork and paint

(h)


Front valuation

Peugeot Expert

Oct-06

1521,97 11.15 39,6 1963,51

Peugeot Partner

Feb-08

1137,17 14.45 39,6 1709,39

Citroën Berlingo

Feb-08

1121,36 14.45 39,6 1693,58

Average 1260,17 13,35 1788,83

Citroën C2 Apr-03

514,73 9.30 39,6 883,01

Toyota Aygo Nov-04

456,01 8.70 39,6 800,53

Peugeot 1007

Dec-04

1172,08 12.70 39,6 1675,00

Toyota Yaris´05

Dec-05

375,16 8.60 39,6 715,72

Renault Twingo II

Sep-07

1276,96 19.05 39,6 2031,34

Toyota iQ Sep-08

992,99 10.30 39,6 1400,87

Average 797,99 11,44 1251,08

Table 7.4 Comparison between commercial vehicles and light passenger cars

7.2. Rear impact assessment

All vehicles have been subjected to an impact by a mobile barrier at a speed of 15 +1 km/h with a 40% overlap. The test specifications are described in section 5.2 of this document.

In case of rear impact, the main features following the RCAR procedure for the chosen vehicles are shown in Table 7.5.


Project nº 266222


Page 40 of 58

Vehicle Mass Engine YearTest date

Test Number

Speed

Ford Fiesta 1113 kg 50 kW 2002 Sep-01 BLS2 2818 15.5 km/h

Toyota Prius 1401 kg 57 kW 2004 Feb-03 - 15.07 km/h

Citroën C2 1031 kg 44 kW 2003 Apr-03 03F388 15.09 km/h

Volkswagen Fox 1060 kg 55 kW 2005 Oct-04 - 15.14 km/h

Toyota Aygo 885 kg 50 kW 2005 Nov-04 990N 15.24 km/h

Peugeot 1007 1236 kg 55 kW 2005 Dec-04 04R735 15.3 km/h

Chevrolet Kalos 1060 kg 69 kW 2005 Oct-05 - 15.03 km/h

Toyota Yaris 1063 kg 50 kW 2005 Jun-05 371L 15.31 km/h

Peugeot Expert 1814 kg 66 kW 2007 Oct-06 06R275 15.1 km/h

Renault Twingo II 1000 kg 43 kW 2007 Sep-07 - 15.1 km/h

Citroën Berlingo – Peugeot Partner

1541 kg 66 kW 2008 Feb-08 07R509 15.8 km/h

Seat Ibiza 1116 kg 63 kW 2008 Feb-08 080801HS 15.25 km/h

Toyota iQ 920 kg 50 kW 2009 Sep-08 630L 15.12 km/h

Audi A1 1115 kg 63 kW 2010 Feb-10 - 15.0 km/h

Citroën C-Zero – Peugeot Ion

1110 kg 35 kW 2010 09/2010 M061250L 15.51 km/h

Toyota Yaris 1115 kg 51 kW 2012 Mar-11 - 15.12 km/h

Table 7.5 Rear impact features following RCAR low speed test in some vehicles

Table 7.6 shows (like for front impact), a general view of vehicle state after the impact, and a description of all elements that have been damaged or deformed after rear impact.


Project nº 266222


Page 41 of 58

Reparability and damageability - Rear impact

Ford Fiesta

Rear bumper, rear bumper brackets, rear crossbeam, rear panel, tailgate, “Ford” trim, “Fiesta” trim, left rear wing reinforcement and left cap flashing

Toyota Prius

Rear bumper, crossbeam, left and right sleeper crush can absorber, rear panel, left rear chassis leg and cargo area floor

Citroën C2

Rear bumper, rear crossbeam-absorber and upper plastic absorber

Volkswagen Fox


Project nº 266222


Page 42 of 58


Rear bumper, rear bumper reinforcement, left rear chassis leg and rear panel

Toyota Aygo

Rear bumper, left bumper molding, rear plate, piece number 2 and 6 and bumper crossbeam

Peugeot 1007

Rear bumper, bumper absorber, bumper crossbeam, bumper molding and rear panel

Chevrolet Kalos


Project nº 266222


Page 43 of 58


Coating bumper, active carbon filter, rear right headlight, rear panel, tailgate, boot floor and rear chassis leg

Toyota Yaris 2005

Rear bumper, bumper crossbeam and rear panel

Peugeot Expert

Photo Non available Rear bumper, rear bumper reinforcement, left rear wheel arch, rear panel and left rear chassis leg

Renault Twingo II

Rear bumper, rear crush can absorber, bumper crossbeam, rear panel, boot floor, tailgate and the exhaust system.

Citroën Berlingo - Peugeot Partner


Project nº 266222


Page 44 of 58


Photo Non available Rear bumper, rear bumper reinforcement and lateral rear bumper bracket

Seat Ibiza

Rear bumper, bumper crossbeam and wheel arch covering

Toyota iQ

Rear bumper, crossbeam, left and right crush can absorber, rear panel, left rear chassis leg, rear left lights and cargo area floor

Audi A1

Photo Non available Rear bumper, rear bumper spoiler and rear bumper support

Mitsubishi iMiEV – Citroën C-Zero – Peugeot Ion

Rear bumper, liner the rear panel, bracket pilot, left floor rail, left rear chassis leg, left rear chassis leg extension, left damper, right damper, stabilizer bar

Toyota Yaris 2012


Project nº 266222


Page 45 of 58


Rear bumper, rear crossbeam, rear bumper reinforcement, rear left lamp, left bumper support and rear panel

Table 7.6 Broken or damage components after rear impact at 15 km/h in each vehicle

The rear, generally, has a lower number of items, so if the car behaves correctly, the number of damaged elements should be smaller compared to frontal impacts.

Table 7.7 shows a large difference between electric vehicles and Renault Twingo II compared to the other vehicles tested. In the three models, final valuation result exceed the 2000 €, while in the others vehicles, the value ranges were between 400 € and 1150 € (except Ford Fiesta). Hybrid models have costs slightly higher than light passenger cars. The best performing model in damageability and therefore lower cost of repair was the Volkswagen Fox, with a valuation of around 380 €.

The three models with higher repair cost needed over 28 hours, and the next one, the Ford Fiesta 2002, whose validation is close to 2000 €, invested nearly 20 hours. The high number of hours increases the cost seriously. The cost of the items was also greater, more than two or even three times the price of the items for other vehicles. This disparity in test results is a consequence of the number of damaged elements and therefore the money and time invested for full repair.

The main reason for high service parts cost in Renault Twingo II is the importance of the affected elements. Tailgate, rear body panel, boot floor and exhaust system increase greatly the final valuation because, in the rest of vehicles these elements are repaired or not damaged instead of replaced.

However, at the opposite point, it is located the Volkswagen Fox, whose low cost is due to the low service parts damage in the rear test. Only the bumper, the end of the left chassis leg, the rear panel and the rear crossbeam were affected, being repaired all of them, except the crossbeam. Figure 7.1 shows in detail the deformation of the rear panel, being the level of damage reparable.


Project nº 266222


Page 46 of 58

Model Test date

Service parts and paint cost

Bodywork and paint (h)


Rear valuation

Ford Fiesta Sep-01 1208,24 19.35 39,6 1974,50

Toyota Prius * Feb-03 522,03 7.60 39,6 822,99

Citroën C2 Apr-03 253,72 8.50 39,6 590,32

Volkswagen Fox Oct-04 141,14 6.05 39,6 380,72

Toyota Aygo Nov-04 373,89 11.35 39,6 823,35

Peugeot 1007 Dec-04 368,86 5.00 39,6 566,86

Chevrolet Kalos Oct-05 678,11 12.10 39,6 1157,27

Toyota Yaris Dec-05 275,92 5.10 39,6 477,88

Peugeot Expert Oct-06 339,67 5.10 39,6 541,63

Renault Twingo II Sep-07 1572,19 28.85 39,6 2714,65

Peugeot Partner Feb-08 273,19 3.30 39,6 403,87

Citroën Berlingo Feb-08 317,03 3.30 39,6 447,71

Seat Ibiza Feb-08 346,63 3.85 39,6 499,09

Toyota iQ Sep-08 410,45 8.80 39,6 758,93

Audi A1 Feb-10 353,75 5.30 39,6 563,63

Peugeot Ion Sep-10 967,54 28.95 39,6 2113,96

Citroën C-Zero Sep-10 967,54 28.95 39,6 2113,96

Toyota Yaris Mar-11 488,64 5.60 39,6 710,40

Table 7.7 Rear impact valuations

Figure 7.1 Detail of the deformation in the left area on the rear panel


Project nº 266222


Page 47 of 58

7.3. Results compilations

The criteria followed for overall assessment of repair is based on accident rates for each type of collision obtained from the annual statistics:

VTR= 0.54 * VFR + 0.16 * VLR + 0.30 * VRR

VTR= Total repair valuation VFR= Front repair valuation VLR= Lateral repair valuation VRR= Rear repair valuation

In case of lateral valuation, damaged elements are estimated as front door, door trim, sill, side windscreen and windscreen regulators. Based on these elements the price of parts and working hours in repair and replacement are valuated. RCAR does not have a test procedure for this type of impact.

In Table 7.8 shows vehicle final valuation for the analyzed vehicles.


Project nº 266222


Page 48 of 58

Model Test date

Front Lateral Rear Total

Ford Fiesta Sep-01

2132,94 1358,33 1974,50 1961,47

Toyota Prius

Feb-03

2189,82 1311,12 822,99 1639,18

Citroën C2 Apr-03

883,01 1252,60 590,32 854,34

Volkswagen Fox

Oct-04

1601,54 1028,40 380,72 1143,59

Toyota Aygo

Nov-04

800,53 1082,58 823,35 852,50

Peugeot 1007

Dec-04

1675,00 1491,74 566,86 1313,23

Chevrolet Kalos

Oct-05

2831,34 1264,67 1157,27 2078,45

Toyota Yaris

Dec-05

715,72 1099,14 477,88 705,72

Peugeot Expert

Oct-06

1963,51 1689,31 541,63 1493,07

Renault Twingo II

Sep-07

2031,34 1411,42 2714,65 2137,15

Peugeot Partner

Feb-08

1709,39 1212,61 403,87 1238,25

Citroën Berlingo

Feb-08

1693,58 1111,13 447,71 1226,63

Seat Ibiza Feb-08

1920,40 1107,26 499,09 1363,91

Toyota iQ Sep-08

1400,87 1074,59 758,93 1156,08

Audi A1 Feb-10

1820,57 1246,95 563,63 1351,71

Peugeot Ion Sep-10

3044,34 1334,22 2113,96 2491,61

Citroën C-Zero

Sep-10

3087,13 1334,22 2113,96 2514,72

Toyota Yaris

Mar-11

1729,56 961,53 710,40 1300,93

Table 7.8 Total valuation resume


Project nº 266222


Page 49 of 58

Figure 7.2 Detail of the electric motor in the PSA vehicle

From the final valuation, the following conclusions are obtained:

Front impact assessment supposes the higher repair cost. Side valuation is very similar for all vehicles, as damage estimation affects same elements

and repair time is very tight. The cost of spare parts therefore determines the price of the lateral valuation.

There is a large disparity in the rear valuation results depending on the number of elements replaced instead of repaired.

The electric vehicle has the highest repairing cost, because of the large number of elements damaged in the crash test, requiring many hours to recover it to its original state. This example is reflected not only in electric models, but also in those like the Ford Fiesta 2002 or the Renault Twingo II.

Commercial vehicles have a similar cost, slightly higher for Peugeot Expert given its larger size.

Light passenger cars have a lower repair cost than heavier vehicles, although the Renault Twingo II is an exception.

In this report an electric and a hybrid model have been studied, with none of the electrical components being affected.

The hybrid vehicle has good behaviour from the point of view of reparability, protecting the more expensive elements. In the rear impact, the high voltage batteries remain intact despite being located behind the rear seats.

The Citroën C-Zero – Peugeot Ion has not been affected in any of its electrical components. The electric motor, located on the rear axle, is not damaged despite the damaged area in the rear of the vehicle, as shown in Figure 7.2.


Project nº 266222


Page 50 of 58

7.4. Analysis of most damaged parts in RCAR test procedure

In the previous section, a damageability and reparability analysis in some vehicles, with similar features than the OPTIBODY prototype was conducted.

In this section, we will proceed to analyze the most damaged parts in the chosen vehicles, both for frontal and rear impact. For side impact, RCAR reports estimate the service parts deformed, being the following: trim, electric window, window, left door and sill. The service parts cost depends basically on the manufacturer, consuming a similar time for all vehicles.

Frontal impact

Analyzing all results it is observed that in all vehicles the first element that absorbs the impact is the front bumper, which must be replaced in all cases, regardless of the type of vehicle. The whole bumper must be replaced, including parts such as pedestrian deflector (if any), reinforcements, foams, brackets, guards, and in some cases, the bumper trim. Brackets are replaced within the segment of light passenger cars, while commercial vehicles are not damaged due to the greater robustness of them.

If vehicles have an item specially designed to absorb impacts, it must also be replaced because it is damaged in all crashes at low speed and it is a non-repairable element. Some vehicles have an independent crush can on the crossbeam. In others, the crossbeam and the crush can are part of the same piece. Commercial vehicles analyzed (Peugeot Expert) have a deformable zone in the end of the rail that does the same function as crush can absorber, avoiding the damage from spreading through the rest of the chassis leg.

The front bumper crossbeam protects the elements located under the bonnet during the low speed impacts; being deformed in more or less degree. In such cases, the crossbeam has to be replaced completely, since its shape does not allow the partial repair. Besides, safety requirements do not allow the repair of this part.

Despite the fact that the bumper absorber boxes and the crossbeams play a very important role in absorbing energy, a part of this energy cannot be absorbed and is transmitted towards the chassis leg ends, that are deformed in greater or lesser degree, so it is necessary to return them to their initial shape. Deformation degree depends also on the type of chassis: a self-supporting body will deform in a greater extent than if a body is mounted on a resistant chassis beam. Therefore, commercial vehicle deformation is lower compared to deformation on light passenger cars.

The front panel is used as anchorage and support of those components located under the bonnet. This protects them in front impact, being affected in approximately half of the studied vehicles, where it has to be replaced or repaired.

Components heavily exposed in the front are the grilles and headlamps which are being replaced in most cases due to fractures in plates or anchorages. Grilles and headlights joints should be easily removable through simple joints.

The hood is one of the parts that most affects the repair since in case of being affected, its high cost increases valuation. In some of the analyzed vehicles, it was severely damaged. However, in others it was slightly damaged, so only repair was needed or just a replacement of the hinges and a correct adjust.


Project nº 266222


Page 51 of 58

Figure 7.3 Example of deformed hood in Seat Ibiza

According to the procedure of RCAR, the frontal impact has a 40% overlap in the driver's side, in order to approximate more accurately the test to accident statistics. This overlap causes that the headlight located in the impacted side was damaged in most cases. The headlight is one of the elements that represent a sudden increase in the cost, and if they can be repaired; it is much more affordable than full replacement. The disadvantage is that the repair is not very common, since there is no access to the damage on both sides, making necessary the replacement.

Other frequently damaged parts at low speed impact are the following ones: outer wings, wheel arch, battery bracket, radiator, air conditioning condenser, engine protection under tray, etc.


Project nº 266222


Page 52 of 58

Vehicle Bumper Crossbeam & Absorber

Grill Hood & hinges

Chassis leg

Front panel

Headlight

Ford Fiesta Replace Replace Replace Replace Repair Replace Replace

Toyota Prius Replace Replace Replace Replace Repair

Citroën C2 Replace Replace Replace Repair Replace

Volkswagen Fox Replace Replace Replace Repair Replace Repair

Toyota Aygo Replace Replace Adjust Replace Replace Dismount /

Mount

Peugeot 1007 Replace Replace Replace Repair Repair Replace

Chevrolet Kalos Replace Replace Replace Replace Replace

Toyota Yaris ‘05 Repair Replace Repair Repair

Peugeot Expert Replace Replace Replace Repair Repair Regulate

Renault Twingo II Replace Replace Replace Replace

Peugeot Partner - Citroën Berlingo

Replace Replace Repair Replace

Seat Ibiza Replace Replace Replace Repair Replace Replace

Toyota iQ Replace Replace Replace Adjust Repair

Audi A1 Replace Replace Replace Replace Replace

Peugeot Ion - Citroën C-Zero

Replace Replace Repair Replace

Toyota Yaris ‘12 Replace Replace Replace Replace Regulate

Table 7.9 Summary of damaged service parts in front impact by vehicle

Rear impact

In rear impacts, the rear bumper is an element frequently replaced due to the serious deformation and cracks suffered, which made a non viable repair. In many cases, plates or bumpers anchorages are damaged and broken, making it too difficult to repair.

The data obtained during the tests indicate that for all vehicles the rear bumper was extensively damaged, becoming more profitable the full bumper replacement. The only exception was found in the Volkswagen Fox, where damaged bumpers were repaired and their final repair costs were the lowest, largely due to this reason and the low number of damaged items.

The crush cans are placed behind absorber bumpers, independently of the bumper reinforcement, and must be completely replaced after crash. In all studied cases, the crush can absorber met its deformation and energy absorption goal, reducing the energy transmitted to the chassis, but forced


Project nº 266222


Page 53 of 58

its full replacement. Energy absorbed in these elements did not prevent that a part of this energy was transformed into a deformation on rear chassis legs.

Regardless of crush can are joined to the crossbeam or not, they must be replaced. Just like in front cases, absorber elements cannot be repaired in any case.

When the energy absorbed by the crush and crossbeam is not enough, some of this energy is transformed into a deformation in the rear panel. It is a part repaired in many cases, because the deformations are not very severe.

Figure 7.4 Detail the damage suffered in the left rear panel of Toyota Prius

An element which indicates the level of damage can be the tailgate. When it had to be replaced, (Ford Fiesta, Citroën C-Zero, Chevrolet Kalos and Renault Twingo II) there was a great number of damaged parts that increase costs considerably. The four major valuations had the tailgate damaged. Some of them, as Chevrolet Kalos, were repaired. However, in others, as the Renault Twingo II, it had to be replaced.

The number of damaged elements depends in many cases on the vehicle design. For example, in some models, like the Citroën C-Zero, it also suffered damage on the suspension elements, such as both damper and stabilizer bar.

In other cases, like Ford Fiesta or Toyota Aygo, the damage extends to the boot floor. The crash produces an energy absorption in the boot floor that is transformed into deformations. This event does not occur in most of the models. However, in those floors deformed; the repair work is very complex and requires a high number of hours spent by the operator.

Other elements damaged in the rear impact are the rear lamps or the rear chassis leg. However, rear validation is lower than front validation due to the lower number of elements in the damaged area.


Project nº 266222


Page 54 of 58

Vehicle Bumper Crossbeam & Absorber

Tailgate Boot floor

Chassis leg

Rear panel

Rear lamps

Ford Fiesta Replace Replace Replace Repair Repair

Toyota Prius Replace Replace Repair Repair Repair

Citroën C2 Replace Replace Dismount / Mount

Repair Dismount / Mount

Volkswagen Fox Repair Replace Repair Repair

Toyota Aygo Replace Replace Repair Repair

Peugeot 1007 Replace Replace Repair

Chevrolet Kalos Replace Replace Repair Repair Replace

Toyota Yaris Replace Replace Repair

Peugeot Expert Replace Replace Repair Repair

Renault Twingo II Replace Replace Replace Repair Replace

Peugeot Partner - Citroën Berlingo

Replace Replace

Seat Ibiza Replace Replace

Toyota iQ Replace Replace Repair Repair Replace

Audi A1 Replace Replace

Peugeot Ion - Citroën C-Zero

Replace Replace Repair Repair Replace

Toyota Yaris´12 Replace Replace Repair Replace

Table 7.10 Summary of damaged service parts in rear impact by vehicle


Project nº 266222


Page 55 of 58

8. Design guide to ensure good design practice for reparability

Throughout this document, the major features about reparability and damageability have been analyzed, obtained from CZ experience as a member of RCAR. The architecture analysis, including the body panels and chassis, allows knowing the elements behaviour in a crash, assessing the damaged area and providing several alternatives to improve service parts repair.

Subsequently to the individual part analysis, we have proceeded to analyze results of RCAR tests in vehicles whose characteristics suit more or less to OPTIBODY concept: commercial, light weight and electric and hybrid vehicles.

As a result of the analysis, several conclusions, showed in the following paragraphs, have been reached. These conclusions should be taken into account in the design, ensuring a good behaviour from reparability and damageability criteria.

Bumper and energy absorber systems

Bumper beams should be replaceable without cutting or welding. They should be attached to the body via energy absorbing structures, which are inexpensive to repair or replace, so structural damage will be prevented.

Good vehicle should incorporate a bumper beam exceeding 100 mm height, making it stable during impacts and preventing underride and override. In addition, it should be torsion-resistant to carry eccentric loads without being twisted.

Crossbeams, both front and rear, should be extended laterally to protect vehicle corners, avoiding the damage of mechanical elements that could be expensive to repair.

Front and rear bumper have a high rate of damageability, forcing them to be repaired or replaced in most crashes. It is therefore a part that receives the first damage, so lightweight materials are being used due to the ability they have to recover shape easily. Design must be optimum according to reparability, and it is necessary to promote the use of threaded joints, rivets or staples instead of welds

Absorbers (crush cans) are essential to achieve good management of the energy generated in the collision. They may be closely joined to crossbeams or independent. Its mission is to act as a fuse at the ends of rails of the vehicle, progressively deforming according to the magnitude of impact.

Front and rear have same needs: to avoid damage in the occupants. Both zones have bumper and crush can whose task is to absorb impact energy. As in front chassis legs, rear chassis legs should have crush cans for low-speed impacts.

Front/rear panel

The front panel is fitted to the chassis legs, supplying a support for both outer wings and hood. The front panel has a high accident rate, which has leaded to a material change in the


Project nº 266222


Page 56 of 58

manufacturing and joining method, becoming bolted rather than welded. It is not recommended to install the front panel on the bumper, crush can or the area of the chassis leg that will not be affected in case of a crash at low speed. Also the front panel´s material has undergone a change, replacing metal by plastic, and even composite.

The rear panel is the most vulnerable part in vehicle rear impacts and many elements such as tailgate, rear bumper and clusters lights are anchored to the rear panel. It is composed of several sheets joined and overlapped in some areas that hinder the independent removal of each one. It should contain the minimum number of elements directly attached to it for decrease the repair time consuming.

Bonnet

It is recommended to move bonnet rearward, increasing the size of the bumper in order to

suffer less damage in low speed impacts.

Cabin/passenger compartment

Normally, A-post and B-post are made by high strength steel, but ultra high strength steel reinforcements are indispensable to reinforce body side pillars. It makes a rigid structure to resist collision efforts and minimize occupant injury risks due to excessive rigidity and the numerous problems to be weld. For this reason, usually it is partially replace instead of completely repaired, but it is indispensable to overlap reinforcements to improve reparability.

If the cabin is considered independent and replaceable as a whole module, then it is appropriate that the union to chassis was bolted. For example with silent blocks. It isolated noise and vibration into the cabin. In turn, complete replacement is possible without spending excessive time. Silent blocks joints have a long tradition in automobile and truck manufacture, especially in suspension and engine brackets. In addition, some light trucks and pickups join the cabin over the chassis with silent blocks.

To design separate zones for doors, with different repairing complexity, will reduce operating times and final costs.

Doors have numerous electric components which must be anchored to the inner frame, so good access should be available.

Chassis platform

As in the front chassis legs, the rear chassis legs have crush cans for low-speed impacts. The rear chassis legs are sandwiched between floor, wheel arch and other closing parts. Separate panels make it easier to remove.

A lack of limitation in damages will increase cost if during the design phase front/rear rails, beams, mounts or brackets were not taken into account. Availability and accessibility for these parts reduce greatly repair time and, finally, the cost. Any consideration must be complemented by appropriate instructions and availability of service parts that fit needs and requirements.

With the aim of avoiding the complex complete replacement of the frame, it is recommended that the chassis legs have a number of sectional areas where proceed to a partial


Project nº 266222


Page 57 of 58

replacement of non-recoverable parts is possible. In partial replacement the location of mechanical systems (brakes, suspension, steering, etc.) has to be taken into account, since they are anchored to the repaired area. Absorber boxes are installed easily and quickly, requiring little time for replacement. Installation must keep in account characteristics of accessibility, material composition, welding features (if possible) and corrosion protection recommendations to avoid damaging to rest of the elements.

Considering the partial replacement, it must be taken into account the economic aspects, in first term, valuing the complete part cost and time invested in its full replacement, or else the option of partial substitution. Furthermore, reutilization, recoverability and recyclability form parts on WP4 are being studied in followings tasks but it cannot be forgotten until last step.

According to the price, it is possible to consider replacing the entire front chassis module provided that they do not have good access to the affected area or there are complex connections between the chassis legs, crossbeam and suspension. Screw or bolt connections must take precedence over welding in those elements most exposed.

If for weight consideration the chassis legs are made of aluminium. Absorption systems should withstand the efforts without transmitting energy to the chassis legs, at least in low speed collisions (e.g. 15 km/h RCAR test). Aluminium repair is more complicated than steel.

Electric system

Electric components location, as a converter, inverter or charging port, must take into account the potentially most damages places. Damageability report shows the increase in the final cost when structural elements with an important task in safety and stability are broken (Renault Twingo II). Similarly, it happens with electrical components, if these components are not properly protected, its replacement will be more expensive.

Throughout different reports carried out, especially in electric and hybrid vehicles (Citroën C-Zero and Toyota Prius), none of the electrical system has been affected after undergoing to RCAR procedure. In both cases, the damage has affected only the body and chassis. High voltage batteries located at the rear axle remain intact. There is no electrical, magnetic or chemical risk after the impact.


Project nº 266222


Page 58 of 58

9. Bibliography

[1] RCAR Design Guide - A manufactures’ guide to ensure good design practice for repairability and limitation of damage. August 2008 [2] RCAR Bumper Test Issue 2.0. September 2010 [3] RCAR Low-speed structural crash test protocol. Issue 2.2. July 2011 [4] CZ. Damageability and reparability report. Ford Fiesta. February 2006 [5] CZ. Damageability and reparability report. Toyota Prius. January 2004 [6] CZ. Damageability and reparability report. Citroën C2. January 2004 [7] CZ. Damageability and reparability report. Volkswagen Fox. September 2005 [8] CZ. Damageability and reparability report. Toyota Aygo. May 2005 [9] CZ. Damageability and reparability report. Peugeot 1007. May 2005 [10] CZ. Damageability and reparability report. Chevrolet Kalos. December 2005 [11] CZ. Damageability and reparability report. Toyota Yaris´05. February 2006 [12] CZ. Damageability and reparability report. Peugeot Expert. March 2007 [13] CZ. Damageability and reparability report. Renault Twingo II. December 2009 [14] CZ. Damageability and reparability report. Peugeot Partner. May 2008 [15] CZ. Damageability and reparability report. Citroën Berlingo. May 2008 [16] CZ. Damageability and reparability report. Seat Ibiza´08. February 2008 [17] CZ. Damageability and reparability report. Toyota iQ. September 2008 [18] CZ. Damageability and reparability report. Audi A1. January 2011 [19] CZ. Damageability and reparability report. Peugeot Ion. April 2011 [20] CZ. Damageability and reparability report. Citroën C-Zero. May 2011 [21] CZ. Damageability and reparability report. Toyota Yaris´12. January 2012 [22] Peugeot Ion Technical manual. Online version http://public.servicebox.peugeot.com/

Date post:	22-Apr-2018
Category:	Documents
Upload:	hakhuong
View:	215 times
Download:	2 times

WP4 DESIGN GUIDE: GUIDE TO ENSURE GOOD...

Documents