Missile TestsA brief presentation by V . Uma maheshwara rao

Introduction• Missiles are generally categorized by their launch platform and

intended target.

• Types of missiles:- - Surface-to-Surface / Air-to-Surface - Surface-to-air - Air-to-air

• Missile Test, Evaluation and Demonstration involves hazardous and high–risk activities. These must be accomplished in time with utmost care to meet program schedules.

• Test and evaluation can be divided in two stages for Missile weapon system:

Ground tests and Flight tests.

Introduction Cont.• Once the weapon system is ready for the flight test, a number of sensors and range instruments are deployed to evaluate the performance of the weapon system during the flight test.

• During the flight test, various parameters like Video data, Trajectory, Range, Altitude. Health parameters like Velocity, Temperature, Pressure, Safety command etc. are monitored and recorded for the real time decision .

• This phase of the test is done through Radio Frequency connectivity and Electro-optics application. Radar Stations, Telemetry (TM) Stations, Electro Optical Tracking Stations (EOTS), Communications, Closed circuit television (CCTV), Flight safety setup, Timing, are few of the critical instruments and sensors deployed while conducting the flight tests.

Why do Tests??• To prove / Fix “system” faults• Build confidence in reliability ( reliability growth

trials)

• Comments : - Missile & spacecraft designers are very cautious

and conservative – don’t like changing things that are flight qualified. - Expense ? Missiles are single use, one-shot

devices. Flight testing can be a significant part of total budget

Terrestrial ConditionsEnvironmental Screening:

- Products are subject to defined stress to find defects in components and PCBs.

- Detecting weak points improves the robustness of the products.

- Shocks and bumps come under environmental screening test.

Pyroshock Testing• A Pyroshock event is used to separate multiple stages of

a rocket, missile, or launch vehicle.

• An explosive device is detonated to break free or separate components .

• This blast causes both a mechanical shock wave and acoustic (airborne) shock wave that propagate through and around the structure. 

• Component and isolation design are so designed that each component or subsystem can survive the event and perform its task.

Vibration Testing•The test is conducted on an electro dynamic shaker

system where the object is FIXTURED to the vibration table.

•This test includes two types of vibration: - Electro dynamic vibration - Repetitive shock vibration

•The computer programming control language used is SAMPAT which stands for :- SIMulated PAckage for test system integration

•Other softwares used – LABVIEW

Electro Dynamic Vibration•This is a closed loop vibration control system

which can accurately reproduce real world vibrations.

•The dynamic features which are affected by using this vibration are: - Displacement - Velocity - Acceleration - Force

Repetitive Shock Vibration•This is generated using one or more pneumatic

impact hammers to strike a plate on which a product is attached.

•This features individual impactor control and monitoring .

•These dual impactors vary both the amplitude and frequency of the strike.

Pneumatic Hammer

There are two basic types of Vibration testings:-

Random Vibration Testing Sine Vibration Testing

Sine Sweep VibrationSine Dwell VibrationSine-on-random VibrationMixed Mode

Sand and Dust Testing•Sand and Dust testing is typically an IP test

 (Ingress Protection).

•Ultimately, these tests are designed to test a component's resistance to a dust-filled environment.

•Exposure to fine dust causes problems with moving parts, forms conductive bridges and acts as an absorbent material for the collection of water vapor.

•In this chamber the real time conditions are stimulated.

•It’s controlled by a small digital controller attached to it.

•The sand and dust are made to blow at desired speeds.

Climatic ObstaclesTemperature

•The life and service of systems are influenced by the varying temperature and climatic conditions during transport and use

•There are different chambers available in order to simulate different temperature conditions

•Temperature chamber along with other factors such as humidity and altitude etc are done in order to test the condition perfectly.

•The temperature chambers can vary from -60o C to +180oC with different rates.

•Thermocouples , thermistors , RTD’s are some of the examples.

Temperature Humidity Chamber

Humidity•Humidity is the presence of water in air.

•When the object is stored in areas near to seashore, it experiences humidity more than the usual places.

•Hygrometers are used in sensing humidity in chambers.

•Electrical hygrometers such as capacitive hygrometers , resistive hygrometers etc are used according to the specified conditions

Corrosion

•Salt Spray Test : The salt spray test chambers and climate alternating test equipment allows selective and reproducible accelerated corrosion testing .

•Dry Corrosion: Corrosive gasses (noxious gasses) in the atmosphere damage materials, components, appliances and buildings.

Emission•To detect and determine the

concentration of undesirable substances, which are released by materials and components of all kinds

•The chamber is constructed from stainless steel with an inner enclosure which is bright annealed, and free from obstructive air-duct systems.

•Temperature, humidity and air exchange in the chamber, aswell as the sampling flow and sampling time, can be easilyprogrammed via the control panel.

Solar Radiation and UV Testing •Fading, yellowing, cracking, peeling, brittleness, loss of

tensile strength, and de-lamination can all occur under UV exposure.

•An accelerated weathering test can help us determine if the product will stand the test of time.

•Solar radiation test is done in order to ensure that the product is safe from different radiations emitted by sun.

•It is placed in a chamber containing a light that emits radiations similar to that of sun.

•It is done to ensure that the product can withstand the intensity of solar radiation.

Icing and Freezing

•To evaluate the effects of icing produced by a freezing rain, mist or sea spray on the operational capability of equipment.

•The building of ice occurs in three principal ways: - From rain on an item whose temperature is below

freezing - From freezing rain on an item at or near freezing - From sea spray which coats equipment when

temperatures are below freezing.

•Ice formation can create problems such as: - Induces structural failures - Reduces airflow efficiency - Affects transmission of electromagnetic radiation - Adds weight to equipment

Areal ObstaclesAltitude

•Altitude testing, is also referred to as low-pressure testing.

•Altitude testing is intended to be used for air shipment of material in a plane, equipment designed for high altitude working.

•This chamber combines temperature and altitude with optional humidity for simultaneous environment testing.

•Users can control the temperature while subjecting the product to various altitudes up to 100,000 feet standard.

•Altitude chambers are used : - Automotive test to simulate mountainous

conditions. - Test electronics that may be shipped via air

freight.

•The pressure variation can cause problems like:•Rupture or explosion of sealed containers.

•Evaporation of lubricants

•Overheating of equipment due to reduced heat transfer.

Thank You