Shock and Vibration Testing Agenda n Shock Testing

Shock and Vibration Testing

Agenda n Shock Testing ¡ Comparison and Selection of Methods n n n Comparison of Specs Rationale for Selection of Testing Vibration Testing ¡ Comparison and Selection of Methods n n Comparison of Specs Rationale for Selection of Testing.

Vibration and Shock

Vibration and Shock Machine Type Range Vibration 20, 000 lb vector, 2 inch displacement Vibration 12, 000 lb vector, 2 inch displacement Vibration 17, 000 lb vector, 1. 5 inch displacement Vibration 6000 lb vector, 1 inch displacement Thermotron Vibration 5 Hammer Repetitive Shock Elite Package Vibration AVCO FF 367 -1 Mechanical Shock AVCO A 105 TIRA Unholz Dicke MB Corp Model C-60 Ling Schaevitz G-6 -A Range Capabilities 5 -2500 Hz 3 axis slip plate; 5 ft. x 5 ft. slip table 5 -2500 Hz 3 axis slip plate; 30 in. x 30 in. slip table 5 – 2500 Hz 3 axis slip plate; 36 in. x 36 in. slip table 5 – 3000 Hz 3 axis slip plate; 30 in. x 30 in. slip table 5 – 2000 Hz 3 axis slip plate; call for size limitations 5 -20, 000 Hz HALT Thermal Shock with vibration 2 – 4 Hz Cam operated bounce test for transportation 300 g’s/20 ms Inquire Sine or saw-tooth Mechanical Shock 30, 000 g’s/0. 02 ms Inquire Sine or saw-tooth Acceleration Limited by 3 ft. arm; Call for size

Vibration and Shock

Vibration and Shock Heating Elements HALT Test Vibration Impactors

Vibration and Shock HALT/HASS Chamber HALT -Highly Accelerated Life Testing • Combined six-axis vibration and temperature extremes. • Intentionally but systematically produces test item failures for the purpose of rapidly identifying mechanical, electrical, design and functional weak points. • Design weaknesses can be analyzed, corrected, and the product design optimized. HASS -Highly Accelerated Stress Screening • Overstress test to identify marginal or defective products before shipment. • HASS test levels are identified during HALT and are established to compress test time without damaging the product or reducing its life.

Vibration and Shock n n n n Elite HALT/HASS Chamber Capabilities -100 C to +200 C (-148 F to +302 F) Greater than +70 C per minute product temperature change rates (heating or cooling) 30” x 30” Vibration Table, 480 lbs total weight capacity for test item & fixture Workspace Dimensions 42”W x 42”D x 40”H Vibration Frequency Range: 2 Hz-10 k. Hz; Vibration Level: Up to 50 Grms Two (2) 3”x 8” access ports, Three (3) 20”x 20” viewing windows

Vibration and Shock Vibration Testing Sine, Random, SOR, Field Data Replication • Record actual vibration levels • Import data to vibration controller • Operate vibration table according to recorded profile and acceleration magnitude • Run test item for endurance • Mechanical Shock • SRS

Vibration and Shock Drop Shock Sawtooth, Half-Sine

Classical Shock Test Machines

Vibration and Shock High G Mechanical Shock

Vibration and Shock High G Constant Acceleration

Vibration and Shock

Fatigue Crack Growth

Vibration and Shock q. Sine Vibration q. From rotating or oscillating machinery; electric motors, wheels, engines, gears, springs. q. Useful for evaluating dynamic characteristics of structures, i. e resonance q. Random Vibration q. More accurately represents the true environment. q. Excites all frequencies Most damage occurs at fundamental frequency of electronics PCB.

Vibration and Shock n Shock ¡ ¡ High stresses causing fracture or permanent deformation High accelerations which can cause relays to chatter, potentiometers to slip, bolts to loosen. High displacement which can cause impact between adjacent circuit boards Usually not considered a fatigue failure if shock quantity less than 1, 000 cycles.

Selecting a Vibration Level or a Shock Pulse n n n 1. 2. 3. Which Shock Pulse should I Apply? How Many? Which Level? What is the vibration spectrum of interest? How long should I test for? Follow the Contract Specifications Create Your Test Based on Existing Specifications as Guidance Make Field Measurements

1 - Follow Contract Requirements

Contract Requirements MIL-PRF-15305

Contract Requirements MIL-PRF-15305 MIL-STD-202 G Method 213

2 - Use Existing Specifications for Guidance n n Military, Regulatory, and OEM Specs Industry Standard Test Methods ¡ n with Recommended Levels Create Your Own Specification

Shock Test Specs & Methods n Automotive ¡ ¡ n Commercial Products ¡ n IEC 68 -2 -27; -29; -31 Commercial Aviation ¡ n FORD, GM SAE J 1455 RTCA DO 160 E Section 8 Military ¡ ¡ ¡ MIL-STD-810 Systems MIL-STD-883 Circuit Cards MIL-STD-202 Components Handling Drop Classical Shock (Potholes & Crashes) Classical Shock Bump Free Fall Operational and Crash Safety Shock Sustained Shock SRS Classical Pyroshock Ballistic Shock

Handling and Free Fall Drop Tests n Drop Surfaces ¡ ¡ n Concrete Steel Wood Sand Package or Device

Typical Classical Shock Tests for Electronic Systems

Typical Classical Shock Tests for Electronic Systems. IEC 68 -2 -27

Elite Capability for Classical Shock n Large Avco (Assume 150 lb load and fixture) ¡ ¡ n Small Avco (Assume 50 lb load and fixture) ¡ ¡ n Short Pulse 3 msec- 300 Gs Long Pulse 30 msec-20 Gs Short Pulse 0. 3 msec- 1000 Gs (longer pulses up to 10 k. Gs) Long Pulse 6 msec-500 gs Tira Electro-dynamic Vibration Table (Assume 150 lb load and fixture) ¡ ¡ Short Pulse 0. 5 msec 150 Gs Long Pulse 30 msec 15 Gs

Classical Shock Pulses n Advantages n n n Easy to specify and understand shape, tolerance, mathematics Test machinery can generate pulses Accepted methods written into many specs Disadvantages n n Not real world pulses Does not evaluate device response to shock

Classical Shock Tests

Classical Shock Tests

Shock Response Spectrum

Shock Response Spectrum Input Pulse Measured Response

Shock Response Spectrum

Shock Response Spectrum

Shock Response Spectrum

Shock Response Spectrum n Preferred method for MIL-810 Describes the Peak Acceleration Response vs. Freq Develop a simple shock pulse that will generate the response function Some ED shakers have SRS capabilities Ringing plates n Pyrotechnic Shock n n

Pyrotechnic Shock

Pyrotechnic Shock

Pyrotechnic Shock

Ballistic Shock

Custom Shock Evaluation n ASTM D 3332 ¡ Damage Boundary n n n Response to short duration pulse is a function of velocity change. Response to long duration pulse is a function of the peak acceleration and waveform. MIL-810 Fragility Test

Vibration and Shock Summary 3. Follow the Contract Specifications Create Your Test Based on Existing Specifications as Guidance Make Field Measurements 4. Call us with your application needs. 1. 2.

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