1. Shock and Vibration Testing

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

3. Vibration and Shock

4. Vibration and Shock Machine Type Range Capabilities TIRA Vibration
20,000lb vector, 2 inch displacement
5-2500Hz
3 axis slip plate; 5 ft. x 5 ft. slip table
12,000lb vector, 2 inch displacement
3 axis slip plate; 30 in. x 30in . slip table
Unholz Dicke
17,000lb vector, 1.5 inch displacement
5 – 2500 Hz
3 axis slip plate; 36 in. x 36 in. slip table
MB Corp Model C-60
6000lb vector, 1 inch displacement
5 – 3000 Hz
Ling
5 – 2000 Hz
3 axis slip plate; call for size limitations
Thermotron
5 Hammer Repetitive Shock
5-20,000 Hz
HALT Thermal Shock with vibration
Elite
Package Vibration
2 – 4 Hz
Cam operated bounce test for transportation
AVCO FF367-1
Mechanical Shock
300g’s/20ms
Inquire
Sine or saw-tooth
AVCO A105
30,000g’s/0.02ms
Schaevitz G-6-A
Acceleration
Limited by 3 ft. arm; Call for size

5. Vibration and Shock

6. Vibration and Shock
Heating Elements
HALT Test Vibration Impactors

7. Vibration and Shock 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.
HALT/HASS Chamber

8. Vibration and Shock Elite HALT/HASS Chamber Capabilities
-100C to +200C (-148F to +302F)
Greater than +70C per minute product temperature change rates (heating or cooling)
30” x 30” Vibration Table, 480lbs total weight capacity for test item & fixture
Workspace Dimensions 42”W x 42”D x 40”H
Vibration Frequency Range: 2Hz-10kHz; Vibration Level: Up to 50Grms
Two (2) 3”x8” access ports, Three (3) 20”x20” viewing windows

9. 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

10. Vibration and Shock
Drop Shock
Sawtooth, Half-Sine

11. Classical Shock Test Machines

12. Vibration and Shock
High G Mechanical Shock

13. Vibration and Shock
High G Constant Acceleration

14. Vibration and Shock

15. Fatigue Crack Growth

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

17. Vibration and Shock 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.

18. Selecting a Vibration Level or a Shock Pulse
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

19. 1- Follow Contract Requirements

20. Contract Requirements MIL-PRF-15305

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

22. 2- Use Existing Specifications for Guidance
Military, Regulatory, and OEM Specs
Industry Standard Test Methods
with Recommended Levels
Create Your Own Specification

23. Shock Test Specs & Methods
Automotive
FORD, GM
SAE J1455
Commercial Products
IEC ; -29; -31
Commercial Aviation
RTCA DO 160E 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

24. Handling and Free Fall Drop Tests
Drop Surfaces
Concrete
Steel
Wood
Sand
Package or Device

25. Typical Classical Shock Tests for Electronic Systems

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

27. Elite Capability for Classical Shock
Large Avco (Assume 150lb load and fixture)
Short Pulse 3msec- 300Gs
Long Pulse 30msec-20Gs
Small Avco (Assume 50lb load and fixture)
Short Pulse 0.3msec- 1000Gs (longer pulses up to 10kGs)
Long Pulse 6msec-500gs
Tira Electro-dynamic Vibration Table (Assume 150lb load and fixture)
Short Pulse msec 150Gs
Long Pulse 30msec 15Gs

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

29. Classical Shock Tests

30. Classical Shock Tests

31. Shock Response Spectrum

32. Shock Response Spectrum
Input Pulse
Measured Response

33. Shock Response Spectrum

34. Shock Response Spectrum

35. Shock Response Spectrum

36. Shock Response Spectrum
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
Pyrotechnic Shock

37. Pyrotechnic Shock

38. Pyrotechnic Shock

39. Pyrotechnic Shock

40. Ballistic Shock

41. Custom Shock Evaluation
ASTM D3332
Damage Boundary
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

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

43. Thank you for this opportunity to serve you.