Shock and Vibration Testing
Agenda
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Shock Testing
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Comparison and Selection of Methods
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Comparison of Specs
Rationale for Selection of Testing
Vibration Testing
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Comparison and Selection of Methods
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
Comparison of Specs
Rationale for Selection of Testing.
Vibration and Shock
Vibration and Shock
Machine
Type
Range
Vibration
20,000lb vector, 2 inch
displacement
Vibration
12,000lb vector, 2 inch
displacement
Vibration
17,000lb vector, 1.5 inch
displacement
Vibration
6000lb vector, 1 inch
displacement
Vibration
6000lb vector, 1 inch
displacement
Thermotron
Vibration
5 Hammer Repetitive
Shock
Elite
Package
Vibration
AVCO FF367-1
Mechanical
Shock
AVCO A105
TIRA
TIRA
Unholz Dicke
MB Corp Model
C-60
Ling
Schaevitz G-6-A
Range
Capabilities
5-2500Hz
3 axis slip plate; 5 ft. x 5 ft. slip
table
5-2500Hz
3 axis slip plate; 30 in. x 30in . 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 30in . 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
300g’s/20ms
Inquire
Sine or saw-tooth
Mechanical
Shock
30,000g’s/0.02ms
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
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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
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
Ultimate Strength
Proportional Limit
Stress
Stress
Yield Strength
Endurance Limit
Strain
Cycles
Fatigue Crack Growth
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.
Vibration and Shock
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Shock
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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
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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-202G Method 213
2- Use Existing Specifications for Guidance
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Military, Regulatory, and OEM Specs
Industry Standard Test Methods
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with Recommended Levels
Create Your Own Specification
Shock Test Specs & Methods
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Automotive
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Commercial Products
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IEC 68-2-27; -29; -31
Commercial Aviation
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FORD, GM
SAE J1455
RTCA DO 160E Section 8
Military
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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
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Drop Surfaces
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Concrete
Steel
Wood
Sand
Package or Device
Typical Classical Shock Tests for Electronic Systems
A(Gs)
A(Gs)
Time (msec)
Time (msec)
Reference Specification
MIL-STD-810F Ground Equipment
ISO 16750-3
Amplitude
Pulse
and Duration Shape
75g-6ms Saw-tooth
50g-6ms
Half-Sine
Quantity
3 pulses x 3 axes x 2 Dir (18 total)
10 pulses x 3 axes x 2 Dir (60 total)
General Motors GMW 3172
General Motors GMW 3172
25g-15ms
100g-11ms
Half-Sine
Half-Sine
132 pulses x 3 axes x 2 Dir (792 total)
3 pulses x 3 axes x 2 Dir (18 total)
Ford Motor
100g-10ms
Half-Sine
6 pulses x 3 axes x 2 Dir (32 total)
RTCA DO-160D (Operational)
RTCA DO-160D (Crash Safety)
6g-11ms
20g-11ms
Saw-tooth
Saw-tooth
1 pulse x 3 axes x 2 Dir (6 total)
1 pulse x 3 axes x 2 Dir (6 total)
Typical Classical Shock Tests for Electronic SystemsIEC 68-2-27
Gs
Time
Wave
Components
Equipment
General handling and transport.
15
11
ST, HS, TR
30
18
ST, HS, TR
30
11
ST, HS, TR
Land based items or items transported
by road, rail or air in secured shock
resistant packages
Installed or tranported in a secured
position on normal road or rail vehicles
or in transport aircraft
Items in secured packages
transported by wheeled vehicles,
aircraft, merchant ships or light
marine craft.
Items in secured packages
transported by full cross country
vehicles. Items mounted in
ST, HS, TR
equipment tranported by or installed
in full cross country vehicles or
aircraft
100
6
500
1
HS
1500
0.5
HS
Structural integrity
semiconductors,
microcircuits.
Structural integrity
semiconductors,
microcircuits.
tests on
integrated circuits,
tests on
integrated circuits,
Items installed or transported in a
secured position in full cross-counry
vehicles. Items carried loose in normal
road or rail vehicles for long periods.
Items used in industrial areas and
subjected to shock from mechanical
handling equipment for example dock
cranes, fork lift trucks.
Elite Capability for Classical Shock
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Large Avco (Assume 150lb load and fixture)
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Small Avco (Assume 50lb load and fixture)
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Short Pulse 3msec- 300Gs
Long Pulse 30msec-20Gs
Short Pulse 0.3msec- 1000Gs (longer pulses up to 10kGs)
Long Pulse 6msec-500gs
Tira Electro-dynamic Vibration Table (Assume 150lb load and
fixture)
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Short Pulse 0.5msec 150Gs
Long Pulse 30msec 15Gs
Classical Shock Pulses
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Advantages
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Easy to specify and understand
shape, tolerance, mathematics
Test machinery can generate pulses
Accepted methods written into many specs
Disadvantages
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Not real world pulses
Does not evaluate device response to shock
Axis1(g's) Axis2(g's) Axis3(g's)
Classical Shock Tests
Engine 3.sif - AccelTH@Axis3.RN_2
15
10
5
0
-5
-10
-15
-20
15
10
5
0
-5
-10
-15
10
5
0
-5
-10
-15
Engine 3.sif - AccelTH@Axis2.RN_2
Engine 3.sif - AccelTH@Axis1.RN_2
0
20
40
60
Time(secs)
80
100
Classical Shock Tests
TmpEdit_0004.sif - AccelTH@Axis3.RN_2
15
10
Axis3(g's)
5
0
-5
-10
-15
-20
0
5
10
Time(secs)
15
20
Shock Response Spectrum
Shock Response Spectrum
Input Pulse
Measured Response
Shock Response Spectrum
Shock Response Spectrum
Shock Response Spectrum
Shock Response Spectrum
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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
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Pyrotechnic Shock
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Pyrotechnic Shock
Pyrotechnic Shock
Pyrotechnic Shock
Ballistic Shock
Custom Shock Evaluation
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ASTM D3332
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Damage Boundary
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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.
Thank you for this opportunity to serve you.