Final Report

JSS MAHAVIDYAPEETHASRI JAYACHAMARAJENDRA COLLEGE OF ENGINEERING, Mysore- 570006(An autonomous institute affiliated to Vishvesvaraya technological university, Belgaum-590018)DEPARTMENT OF MECHANICAL ENGINEERING A Project report onDESIGN AND FABRICATION OF MOULD FOR FATIGUE TEST SPECIMEN Submitted in partial fulfilment of the requirements for the award of bachelors degree in Mechanical EngineeringBYSubramanya.Parande 4JC10ME058 M.Noor Khalandar 4JC10ME033 Akash.S.Biradar 4JC10ME002

UNDER THE GUIDANCE OFDR. N.D.JAWALI,Professor ,Department of Mechanical Engineering,SJCE, Mysore

ABSTRACT This project deals with design and fabrication of the mould or tool for the preparation of a circular polymer composite specimen which will be subjected to fatigue test. The very importance of this project lies in its ability to replace metallic elements with that of polymers. Now a days research is being done to apply new materials for the existing components. Therefore there are several methods by which this can be obtained, one such method is slush moulding. The process of tool making involves a series of direct stages, which completes in a proper planning and proper thinking and co-ordination must result in a successful tool. This project report has been prepared with an outlook to import optimum, information about a tool in a more easily grasping in a short span of time. We have made an earnest attempt to cover the entire process of tool making process considering the various steps involved to make the mould in a safe and fastest method and a high degree of accuracy in its functional aspects while manufacturing the tool within the specified cost and time.

2013-2014JSS MAHAVIDYAPEETHASRI JAYACHAMARAJENDRA COLLEGE OF ENGINEERING, Mysore- 570006(An autonomous institute affiliated to Vishvesvaraya technological university, Belgaum-590018)DEPARTMENT OF MECHANICAL ENGINEERING

CERTIFICATE

This is to certify that the project work entitled DESIGN AND FABRICATION OF MOULD FOR FATIGUE TEST SPECIMEN is a bonafide record of the work carried out by Subramanya.Parande (4JC10ME059), Marur Noor Khalandar (4JC10ME033) and Akash.S.Biradar (4JC10ME002) students of final year B.E., in partial fulfilment of the requirements for the award of the degree of B.E in Mechanical Engineering, during the year 2013-2014.

GUIDEPRINCIPALDr. N.D.JAWALI Dr. Syed Shakeeb Ur Rehman,Professor, SJCE, MysoreDept. of Mechanical Engineering

EXAMINERS NAMESIGNATURE

I. ..........II. .III. ..

DECLARATION

We, the students of final semester B.E in Mechanical Engineering, Sri Jayachamarejendra College of Engineering, Mysore, hereby declare that dissertation entitled DESIGN AND FABRICATION OF MOULD FOR FATIGUE TEST SPECIMEN, has been carried out under the guidance of Dr.N.D.JAWALI, Professor, Department of Mechanical Engineering, SJCE, Mysore and Submitted in partial fulfilment of the requirements for the award of Bachelor of Engineering degree in Mechanical Engineering by Visvesvaraya Technological University, Belgaum during the academic year 2013-14. Further the matter presented in this dissertation has not been submitted previously by us or anybody for the award of any degree or diploma to any other university.

Subramanya.Parande (4JC10ME058) Marur Noor Khalandar (4JC10ME033) Akash.S.Biradar (4JC10ME002)

Place: MysoreDate:

ACKNOLEDGEMENTSWe take this opportunity to express our sincere gratitude and remain deeply indebted to those who helped us to finish this project work successfully.

Firstly, we would like to thank our Principal, Dr. Syed Shakeeb Ur Rehman for his co-operation and encouragement during the course of my project.

We remain indebted to our project guide Dr.N.D.JAWALI, Professor, Department of Mechanical Engineering for supervising and supporting me throughout this project.

It is a pleasure to express our deep sense of gratitude and profound thanks to Mr.Manjunath for guiding us in the right direction.

We extend my sincere thanks to Mr.Arun for guiding us in the right direction from the beginning of this project without which our successful completion of the project work would have been difficult.

Subramanya.Parande Marur Noor Khalandar Akash.S.Biradar

CONTENTS

ABSTRACT .CERTIFICATE .DECLARATION ..ACKNOWLEDGEMENTS LIST OF FIGURES.LIST OF TABLES .

CHAPTER 1: INTRODUCTIONCHAPTER 3: LITERATURE REVIEWCHAPTER 4: OUTLINE OF STUDYCHAPTER 6: RESULTS AND DISCUSSIONSCHAPTER 7: CONCLUSIONCHAPTER 8: SCOPE FOR FUTURE WORK

LIST OF FIGURESFigure no.Figure descriptionPage no.

1.1

1.3

4.1

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

5.10

LIST OF TABLESTable no.Table NamePage no.

4.1

4.2

4.3

4.4

4.5

5.1

CHAPTER 1INTRODUCTION

Any product to be manufactured invariably requires tools. Tool design and development is a specialized and critical area. Since tool is an aid for mass production it should be accurate and economical for successful life of a product. In 1860s there was invention of the first plastic, cellulose nitrate .plastics are hydrocarbons consisting of large chains of carbon and hydrogen atoms. Plastics dont resemble each other either in appearance or characteristics. There are two types of plastics: 1. Thermo set plastics 2. Thermo plastics

Thermoplastics There are a wide range of thermoplastics, some that are rigid and some that aree extremely flexible. The molecules of thermoplastics are in lines or long chains with very few entanglements. When heat is applied the molecules move apart, which increases the distance between them, causing them to become untangled. This allows them to become soft when heated so that they can be bent into all sorts of shapes. When they are left to cool the chains of molecules cool, take their former position and the plastic becomes stiff and hard again. The process of heating, shaping, reheating and reforming can be repeated many times.

Long chain molecules

Thermo set plastics The molecules of thermosetting plastics are heavily cross-linked. They form a rigid molecular structure. The molecules in thermoplastics sit end-to-end and side-by-side. Although they soften when heated the first time, which allows them to be shaped theybecome permanently stiff and solid and cannot be reshaped. Thermoplastics remain rigid and non-flexible even at high temperatures. Polyester resin and urea formaldehyde are examples of thermosetting plastics.

Cross-linked molecules

MOULDING Molding of plastics comprises of forming an article to the desired shape by the application of heat and pressure to the moulding component in a suitable mould and hardening the material in the mould

TYPES OF PLASTIC MOULDING:-ExtrusionThe extrusion molding process begins with raw plastic such as pellets, powder or beads. A hopper feeds the plastic into a revolving chamber. The chamber, called an extruder, turns and melts the plastic. The melted plastic is forced out of a die and becomes the shape of the finished product. The item is dropped onto a conveyer belt, where it is cooled with water, cut and finished. Items Products made by extrusion include sheets, film and pipes.

Injection MouldingInjection moulding uses the same principle as extrusion. The raw plastic is fed from a hopper to a melting chamber. However, instead of being forced out of a die, the melted plastic is forced into a cold mould under high pressure. Once the mould cools and solidifies, the product is cleaned and finished. Products made by injection moulding include butter containers, bottle caps, toys and lawn furniture.

Blow MouldingBlow moulding is a process that uses a blowing method after extrusion or injection moulding. Extrusion blowing uses a die that creates a heated plastic tube with a chilled mould around it. Compressed air is blown through the tube to force the plastic to conform to the shape of the inside of the tube. This allows manufactures to create a continuous, uniformly melted, hollow shape without having to attach separate injection-moulded parts. Injection blowing still uses an injection mould, but instead of a finished product, the mould is an intermediate form that is heated to be blown into a final shape in a different cold mould.

Compression MouldingCompression moulding is the process of taking a pre-specified volume of plastic material, putting it into a mould, and then using another mould to flatten or compress the plastic into the previous mould. The process can be automated or manual, and it can use either thermoplastics or thermosets.

ThermoformingThermoforming is the process of taking heated film and softening it to conform to a mould shape. The film is not melted, but heated so that it can be soft enough to be pressed into a mould. The manufacturer forces the plastic into the desired shape through the use of high pressure, a vacuum or a plug. After the finished product has cooled, it is sheared from the mould and scraps are recycled to be put in new film.Slush MouldingSlush moulding is a closely related but somewhat different technique to dip moulding and is used for the production of flexible and semi-rigid mouldings where a detailed surface finish is required on the outside of the moulding. Whereas a male former or tool is used to produce a dip moulding reproducing the tool surface on the inside of the moulding, slush moulding enables you to produce the fine detail effects on the outside of the moulding using a hollow female mould or tool, in effect, the reverse of dip moulding.

The mould is pre-heated then filled with liquid material to a pre-determined level, subsequently the curing process starts resulting in the desired wall thickness. The remaining liquid material is then decanted and final curing takes place, after which the tool is cooled and the finished moulding is stripped from the mould.

The process needs either, fabricated steel, cast or machined aluminium tools and it is because such tooling in inexpensive, by comparison with, for instance, injection or blow moulding, that small and medium quantities can be moulded allowing considerable design freedom. Typical applications are toys, dolls heads, manikin models, containers, balls, large gaiters and many others.

OBJECTIVE OF THE PROJECT:- To fabricate the mould for the preparation of plastisol specimens using slush moulding technique.

CHAPTER 2COMPANY PROFILE

CHAPTER 3LITERATURE REVIEW Y.A.Khalid,S.A.Mutahser,V.B.Sahari,A.M.S.Hamouda [1] Obtained results by increasing the number of layers would enhance the fatigue strength of composite tube up to 40%.

Sagar R D, Sachin G M,Jayant P G,Neelesh D K [2] obtained result that replacement of conventional drive shaft result in reduction in weight of automobile.

Mohammed Reza k, Amin Paykani,Aidin Akbarzadeh[3] have concluded that a one piece composite driveshaft is considered to be replaced a two piece steel driveshaft.

3.1 CONCEPTS REFERRED

Fundamentals of Turbo-machinery, Types of fans and their applications, Impeller design,Different types of Housing design for fans and blowers.Modelling Aid Fundamentals of CAD, Geometric Dimensioning &Tolerance (GD&T), Types of Projections, etc. Analysis Aid - Stress-Strain relationship for ductile and brittle materials, Theories of Failure, Fundamentals of Finite Element Analysis (FEA) like: Types of Contacts, stiffness matrix, Meshing Element types and sizing, Mapping of Mesh, etc.3.2SOFTWARES USED3.2.1 SOLIDWORKS 2012 PREMIUMSolidworks Premium is a comprehensive 3D design solution that possesses powerful motion simulation, design validation, ECAD/MCAD collaboration, reverse engineering and advanced wire and pipe routing functionality. This CAD software offers an easy to use set of tools for 3D and 2D design of any system. It has the capability to create shape based and operation based features. Various viewing options in the software provide a better way for the study of 3D model. Editing options available are very much user friendly.3.2.2 ANSYS14.5 WorkbenchIt is a framework upon which advanced engineering simulation technology are built. Its project schematic view ties together the entire simulation process, and guides to even more complex multi physics analyses with drag and drop simplicity. It provides bidirectional CAD connectivity, powerful and highly automated meshing, project level update mechanism, pervasive parameter management and integrated optimization tools. This enables simulation driven product development. It includes CAD integration technology in CAD neutral CAE integration environment. This integration has named selection manager. This feature is used to create custom attributes within CAD systems that can be directly used in ANSYS application for modelling, meshing and analysis. ANSYS Workbench is an integration of Design Modeller and ANSYS Mechanical/Structural module. These modules together in a single window provide a better way of organising the analysis tree.3.2.3 Design ModelerIt is a gateway to geometry handling for analysis.Built on the Para solid geometric modeling kernel, the geometry engine is robust and conforms to industry standards. It has connections to all major CAD systems, which allows seamless transfer of existing data including parameters. Any CAD model usually includes details that are not needed for simulation such as logos and other small features. Simulating such a fully detailed model increases the solver run time. It is efficient to spend a short time removing these details to reduce the total run time by hours or days. ANSYS Design Modeler product is fully parametric. This is combined with parametric meshing and parametric solver setup within the ANSYS Workbench platform so that the same geometry can be used for multiple design variations.3.2.4ANSYS MechanicalMesh generation is one of the most critical aspects of engineering simulation. Too many elements results in long solver runs, and too few leads to inaccurate results. In ANSYS Mechanical, the meshing technology provides a means to balance these requirements and obtain the right mesh for each simulation in the most automated way possible. ANSYS Meshing technology has been built on the strengths of standalone, class leading meshing tools. The strongest aspects of these separate tools have been brought together in a single environment to produce some of the most powerful meshing available. ANSYS Structural simulation doesnt require very high quality meshes and smoothness of size changes; rather it calls for an optimized meshing and mapping of elements. ANSYS meshings physics preference setting ensures the right mesh for the simulation. Highly automated meshing environment makes it simple to generate tetrahedraltype of meshing. Easy user controls make mesh settings very straight forward. Mesh connectivity is maintained automatically.

CHAPTER 4OUTLINE OF STUDY

4.1 Design of the StudyI. The existing model of the mixed flow fan is modelled part by part in Solidworks Premium 2012. The assembly is created in Assembly workbench of the software.II. A .step file of the assembly is saved which is later imported to ANSYS workbench. III. This model is taken into ANSYS workbench and analysed with designed loading conditions.IV. The same model is applied with the new loading conditions, analysed and interpreted to suit the design requirements.V. If the component is found to satisfy the design requirements, the same model is approved. Otherwise, suitable changes are made to profile or to the features where the attention is required in Solidworks and a .step file is created.VI. Steps 3 and 4 are repeated for the modified model.VII. Afinal model satisfying all the design requirements is obtained and reported.4.2DATA COLLECTION4.2.1 Loading ConditionsTable 4.1: Specified Loading details for the StudyType of loadAcceleration Pressure in MPaCap loads in N

Component direction

X YZ

Face 1Face 2

Old loading conditions+20g+20g+20g0.51608.501036.30

New loading conditions+20g+20g+20g13217.002072.61

4.2.2 Material Information4.2.2.1 ALUMINIUM ALLOY BS1490 LM-25-TFLM25 is mainly used where good mechanical properties are required in castings of shape or dimensions requiring an alloy of excellent castability in order to achieve the desired standard of soundness. The alloy is also used where resistance to corrosion is an important consideration, particularly where high strength is also required. TF represents Fully Heat Treated condition.Table 4.2: Mechanical properties of Aluminium Alloy BS1490Youngs Modulus71 GPa

Poissons Ratio0.33

Density2680 kg/m3

Tensile Yield Strength200 MPa

Tensile Ultimate Strength230 MPa

Elongation0 1 %

4.2.2.2 STAINLESS STEEL BS970 416-S-21Martensitic (Magnetic) in nature, can be hardened and tempered to give improved tensile strength. Typical applications include spindles, Rotor cores and shafts, fasteners, valves, surgical instruments, cutlery.Table 4.3: Mechanical properties of Stainless Steel BS970Youngs Modulus196.5 GPa

Poissons Ratio0.25

Density7999.5 kg/m3

Tensile Yield Strength413.7 MPa

Tensile Ultimate Strength689.5 MPa

Elongation13 15 %

4.2.2.3 STRUCTURAL STEEL This material is found in Engineering Material Library of ANSYS 14.5 engineering data workbench. It is default recommended by ANSYS to use this material if material data is not given. Here this material is applied to all the nuts, bolts, washers and screws found in the assembly.Table 4.4: Mechanical properties of Structural SteelYoungs Modulus200 GPa

Poissons Ratio0.30

Density7850 kg/m3

Tensile Yield Strength250 MPa

Tensile Ultimate Strength460 MPa

4.2.3 Main parts of the assembly:Table 4.5: Material and quantity information of important components of the Fan AssemblySl. No.Component NameNumber of ItemsMaterial Standard

1Casing1Al alloy BS1490

2Guide Vane Assembly1Al alloy BS1490

3Impeller1Al alloy BS1490

4Main Shaft1Stainless Steel BS970

5Shaft Key1Stainless Steel BS970

6Rotor Core Assembly1Stainless Steel BS970

7Case Electronics1Al alloy BS1490

8End Cover1Al alloy BS1490

9End Plate Assembly1Al alloy BS1490

10PCB1Al alloy BS1490

11Bearing Liner2Stainless Steel BS970

12Radial Ball Bearing2Stainless Steel BS970

13Magnet Carrier & Mould Assembly1Stainless Steel BS970

14Location Ring1Stainless Steel BS970

15All nuts, bolts ,screws & washers--Structural Steel

Fig 4.1: Cross-sectional view of the Fan Assembly

CHAPTER 5ANALYSIS PROCEDURE5.1DESIGN CONSIDERATIONS: Recommended Modelling Software- SOLIDWORKS PREMIUM 2012 Recommended Analysis Software ANSYS Workbench 14.5 The assembly is to be analysed only under Static Structural System of the ANSYS workbench. Modal and Random Vibration System analysis is beyond the scope of this project. Material Facts are not to be changed for any of the part belonging to the assembly. The system is to be studied under Worst-case environments. During Meshing in ANSYS, the sizing of elements and mappingof specific regions (if required) should be optimised and should be kept the same throughout the Iterative study.5.2 PART MODELLING AND ASSEMBLY: Draft copies of all the parts which make up the Mixed Flow Fan are obtained. Part modelling of all the components is carried out in Solidworks Premium Part Workstation and saved as individual .sldprt files. Part modelling of standard Bolts, nuts, washers and screw are avoided as these components can be directly included into the assembly workstation through the Solidworks Toolbox Library. Further, the central Main Shaft is first taken into the Assembly Workstation of the Solidworks and is made fixed. One after the other, all the individual part files are launched to assembly workstation.Bottom - up assembly method is followed as it is handy and easier. The parts are mated and constrained as specified in the Final Assembly Draft given as input to the project. If interference is found between parts, the parts are checked for accurate dimensions ion draft and modified. Bolts, nuts, washers and screw are brought from toolbox library and added wherever necessary with the given specifications. The fix feature applied to centre shaft is removed and is all degrees of freedom (DOF) are constrained except rotation about its longitudinal axis. Casing and Guide Vane Assembly pats are made fixed as these are only two parts which are firmly bolted to other systems or duct.5.3STUDY OF THE 3-D MODEL:

Straightening vanes

Fig5.1: 3D cross-sectional view of the assembly showcasing air flow

This 3D model of mixed flow inline duct fan was examined. Parts of the Fan assembly are as shown in Fig. 5.1& Fig 4.1. Air enters the Impeller eyethrough opening in the casing due to low pressure created by rotation of the impeller. Air is diverted as shown in Fig 5.1, further it is straightened by 12 Guide vanes which are present in the Guide vane assembly. This air is ducted out for coolingessential drive components,densely packed electronic equipment, or systems having high or variable resistance such as filters and small electric actuator or drive motors

5.4 Housing of the Fan Assembly:

Guide vane AssemblyCasingFig 5.2: casing and Guide vane Assembly parts make upthe Housingfor the fan assemblyThe analysis study is mainly concentrated on two parts of the Fan assembly namely- CASING and GUIDE VANE ASSEMBLY. This is because the entire Fan assembly is connected to flange or duct through eighthole locations of casing and guide vane assembly. As the dissertation deals with only Structural analysis, it is a requirement of study report to be focussed on main load bearing/supporting part(s).

5.5 Analysis Considerations and Assumptions:5.5.1 Environment conditionsThe system is analysed onworst-case environment conditions, in which- The system has to be analysed with giving Acceleration loading individually in all the 3-directions along with other loads. Fixed support regions are reduced to four fastening regions which are inGuide Vane Assembly part.5.5.2 Point Mass As discussed in item 5.4, though the study is focussed on housing of the Fan assembly, it becomes inappropriate to completely neglectthe effect of internal components on results & conclusions. Hence, a calculated point mass is added at the centroid of the support faces of housing to simulate the net effect of the internal components.Point mass is: 0.31654 kg

Fig 5.3point mass shown as a lump at the centroid of the support faces (red faces)

5.5.3 Bonded ContactIt is clear from the assembly that the type of connection between Casing and Guide Vane Assembly is through Hexagonal socket Head cap Screw ISO 4762 M3 x 10. The analysis requirement is to neglect the stress at this fastener location and make it as a bonded contact for easy, time valuing simulations and results.

Fig 5.4 Red and Blue coloured faces depicting bonded contact regions5.6 Meshing5.6.1 Element sizeAuto generated Meshing size in ANSYS APDL Workbench is found to be too coarse. Hence, a Body Sizing of element size 3mm is given to the housing.

Fig 5.5 Entire Housing is Body sized to 3 mm element size5.6.2 Mapped MeshingHaphazard, Irregular meshes are the reasons for generation of Singular stress. Hence, a mapping is given to regions of greater concerns.

Fig 5.6 Purple coloured faces showing Mapped Mesh regions5.7 SupportsAs per the environment conditions discussed in 5.5.1, the four mounting holes on the Guide vane Assembly are constrained in all degrees of freedom. This makes it as Fixed Support.

Fig 5.7 Four mounting holes of Guide Vane Assembly are made Fixed Supports

5.8Loading5.8.1 Acceleration LoadsSimulation runs are carried out by applying acceleration loads in only one direction at a time.

Fig 5.8 Housing loaded with 20g acceleration load in X, Y & Z-axes

5.8.2 Pressure loadingPressure is applied on all the 44 inner faces where the air comes in contact with as shown in Fig 5.9.

Fig 5.9 Pressure Load applied on all the inner faces of the Housing5.8.3 Cap loadingA component or vessel when subjected to pressure loading, experiences stresses in all directions. The normal stresses resulting from the pressure loading are the functions of diameter of the component. These normal stresses are called Cap stresses or cap loads.Mathematical formula to calculate Cap load is:F = P*AWhere,F ------ Force (N)P ------ Pressure (N/mm2 or MPa)A ------ Area (mm2)Table 5.1:Details of Cap loading Pressure(MPa)INLETOUTLET

Diameter (mm)Area (mm2)Force (N)Diameter (mm)Area (mm2)Force (N)

D1D2

0.56432171608.5074.1453.502072.611036.30

1.03217.502072.61

Fig 5.10 Faces on which Cap loads are acted upon5.9 InterpretationThe housing after simulation is analysed according to Maximum Principal Stress Theory. This is because of two reasons- The material of housing as given in table 4.2.3 is Aluminium Alloy BS1490. From its Mechanical properties table, it is clear that the material behaves as brittle material since its Elongation is < 5%. The process of manufacturing the part is by Sand casting method. Castings are normally considered as brittle.5.10 Casting Factor and Factor of SafetyCasting Factor: To negotiate for the defects in casting process, the Ultimate Tensile Strength of the material is reduce by certain units, which is called CASTING FACTOR. This ensures the design to be safe even under operating extremities.For Aluminium casting, Casting Factor is taken as 0.85Factor of safety (FoS):Factor of Safety is a ratio of absolute strength (structural capacity) to allowable or permissible load. This is a measure of the reliability of a particular design.Mathematically,

In this case Factor of Safety is taken as 2.5.11 Design Strength of the Housing:After considering the Casting Factor and Factor of Safety, the permissible stress or design strength of the housing is

Allowable Stress = 97.75 N/mm2

CHAPTER 6RESULTS AND DISCUSSION

6.1 SIMULATION RESULTSOF ORIGINAL CASING FOR OLD LOADING CONDITIONS6.1.1 Acceleration loading in X-axis

Fig 6.1 Total deformation plots

The Maximum Principal Stress observed on the Guide vaneis a singular stress. Hence ignored.

Fig 6.2 Stress distribution on the housingaccording to Maximum principal stress

The Maximum Principal Stress of 97.243 MPa is observed on the Casing as shown.

Fig 6.3 Stress distribution on Casing according to Maximum Principal Stress

6.1.2 Acceleration loading in Y-axis:

Fig 6.4 Total Deformation Plots

The Maximum Principal Stress observed on the Guide vane is a singular stress. Hence ignored.




6.1.3 Acceleration loading in Z-axis:





Fig6.9 Stress distribution on Casing according to Maximum Principal Stress

6.1.4 InferenceThe given housing is simulated with old loading conditions .It is evident from the deformation and Maximum Principal Stress plots of content 6.1.1, 6.1.2, 6.1.3 that the housing designis within the allowable or design strength of 97.75 N/mm2.

6.2 SIMULATION RESULTS OF ORIGINAL CASING WITH NEW LOADING CONDITIONS6.2.1 Acceleration loading in X-axis:

Fig 6.10 Total deformation Plots


Fig 6.11 Stress distribution ploton the housingaccording to Maximum principal stress


Fig 6.12Stress distribution on Casing according to Maximum Principal Stress

6.2.2 Acceleration loading in Y-axis:

Fig 6.13 Total deformation Plot

The Maximum Principal Stress observed on the Guide vane is a singular stress. Henceignored.

Fig 6.14 Stress distributionon the housingaccording to Maximum principal stress



6.2.3 Acceleration loading in Z-axis






6.2.4 Inference:In Chapter 6.2, the housing is loaded as per the new design specification and calculations. It is clearly evident from the plots of content 6.2.1, 6.2.2, 6.2.3, that the given housing design fails at NECK or FILLET region of Casing part. Hence, a suitable change is to be made and simulated with the same loading conditions.

6.3 STUDY OF THE GIVEN CASING

Fig 6.19 Dimensional details of the given Casing partSince the Maximum stress region is found to be the Fillet region, it is possible to obtain a better design by changing the fillet size. The fillet size of the given casing is found to be 2.50mm.

6.4 DESCRIPTION OF MODIFIED CASINGThe Dimensional detail of the given Casing is carefully studied. Considering the inlet flange dimension of 3mm and also by an intuitive approach to design, it is advisable to increase the fillet size to 3.00mm.Hence, the fillet size is changed to 3.00 mm and the housing is simulated.

Fig 6.20 Dimensional details of the modified Casing part

6.5 SIMULATION RESULTS OF MODIFIED CASING FOR NEW LOADING CONDITIONS6.5.1 Acceleration loading in X-axis






6.5.2 Acceleration loading in Y-axis






6.5.3 Acceleration loading in Z-axis:






6.5.4 Inference:In Chapter 6.3, Simulation results of modified Casing are obtained. It is clearly evident from the Deformation and Stress plots in content 6.3.1, 6.3.2, 6.3.3, that the dimensional change of the fillet has affected the results. A maximum stress of 143.35 N/mm2 is observed at the fillet region when the acceleration loading in in X-axis. Since the allowable or design stress is 97.75N/mm2, there is a necessity of altering the dimensions in the fillet region of the Casing.

6.6 DESCRIPTION OF THE GEOMETRY OF 2ND MODIFED CASING

FLANGESLOPEFig 6.30 Dimensional details of the 2nd modified casingIt is observed from Chapter 6.3, that an increase in fillet size by just 0.5mm has reduced the stress in the region by approximately 50 N/mm2. Hence, for the next iteration, increasing the fillet size is considered.However, if a fillet size increase to 3.50 mm is employed, the results of the design may be come under safe limits, but, there comes violation of SMOOTH TRANSITION between flange and slope as flange thickness is 3 mm and the slope thickness 3.33 mm. Hence, a fillet size obtained by averaging slope and flange thickness is taken, which is 3.20 mm. Additional to this, a step of 1 mm thickness as show in Fig 6.36 is added to compensate for the reduced increment level of fillet size.6.7 SIMULATION RESULTS OF FINAL CASING WITH NEW LOADING CONDITIONS6.7.1 Acceleration loading in X-axis






6.7.2 Acceleration loading in Y-axis






6.7.3 Acceleration loading in Z-axis






6.7.4 Inference:Deformation and Maximum Principal Stress Plots for the latest modified Casing is obtained and studied. It is evident from the results that Maximum Stress is obtained for Acceleration loading in X-axis and its value is 72.391 N/mm2.Since this value of Maximum Stress is below the Allowable or Design stress of 97.75 N/mm2, the housing is said to be adhering to all the design consideration and specifications.

CHAPTER 7CONCLUSIONThe objective of the project work is to study the Housing of a Mixed Fan assembly under the new Military Design specifications, and to ensure the housing adheres to the design requirements and considerations. The given assembly was simulated in Static Structural system of ANSYS Workbench and it was found that the Casing part of housing was breaking down for the new loading conditions. Hence, suitable geometrical design changes are made to the concerned regionand simulated in an Iterative manner.Thefinal design shown in Fig 6.30 is found to satisfy all the design requirements and considerations.

CHAPTER 8SCOPE FOR FUTURE WORKThis Project work is constrained to only Static Structural analysis. The Modal analysis, Harmonic response analysis and Random Vibration analysis is out of the scope this project.The Fan Assembly can be studied under the above listed systems of the ANSYS Workbench by obtaining suitable design data and study pattern information. However, all discussions, inferences and conclusions made in this Projectmust be considered while doing future study or while making changes to the geometry of the housing when fresh requirements are dealt with.

BIBLIOGRAPHY1. Gere J. M. And Goodno B.J., Mechanics of Materials, Cengage Learning, 7th Edition, 2012.2. John May, British Standard Specification for Wrought steel for mechanical and allied engineering purposes, Powertrain Ltd., February 20, 2002.3. 4. 5. 6. 7. http://www.hadleighcastings.com/uploads/LM25%20Alloy%20Detail.pdf1

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