mechanical shock and vibration testing

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Shock and Vibration Testing

AgendaShock Testing

Comparison and Selection of Methods

Comparison of Specs Rationale for Selection of Testing

Vibration Testing

Comparison and Selection of Methods

Comparison of Specs Rationale for Selection of Testing.

Vibration and Shock

Vibration and ShockMachineTIRA TIRA Unholz Dicke MB Corp Model C-60 Ling Thermotron Elite AVCO FF367-1 AVCO A105 Schaevitz G-6-A

TypeVibration Vibration Vibration Vibration Vibration Vibration Package Vibration Mechanical Shock Mechanical Shock Acceleration

Range20,000lb vector, 2 inch displacement 12,000lb vector, 2 inch displacement 17,000lb vector, 1.5 inch displacement 6000lb vector, 1 inch displacement 6000lb vector, 1 inch displacement 5 Hammer Repetitive Shock

Range5-2500Hz 5-2500Hz 5 2500 Hz 5 3000 Hz 5 2000 Hz 5-20,000 Hz 2 4 Hz

Capabilities3 axis slip plate; 5 ft. x 5 ft. slip table 3 axis slip plate; 30 in. x 30in . slip table 3 axis slip plate; 36 in. x 36 in. slip table 3 axis slip plate; 30 in. x 30in . slip table 3 axis slip plate; call for size limitations HALT Thermal Shock with vibration Cam operated bounce test for transportation Sine or saw-tooth Sine or saw-tooth

300gs/20ms 30,000gs/0.02ms Limited by 3 ft. arm; Call for size

Inquire Inquire

Vibration and Shock

Vibration and Shock

Heating Elements HALT Test Vibration Impactors

Vibration and ShockHALT/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

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 42W x 42D x 40H Vibration Frequency Range: 2Hz-10kHz; Vibration Level: Up to 50Grms Two (2) 3x8 access ports, Three (3) 20x20 viewing windows

Vibration and ShockVibration TestingSine, 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 ShockSine 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

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

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. 2. 3.

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

Military, Regulatory, and OEM Specs Industry Standard Test Methods

with Recommended Levels

Create Your Own Specification

Shock Test Specs & Methods

Automotive

FORD, GM SAE J1455

Handling Drop Classical Shock (Potholes & Crashes) Classical Shock Bump Free Fall Operational and Crash Safety Shock Sustained Shock

Commercial Products

IEC 68-2-27; -29; -31

Commercial Aviation

RTCA DO 160E Section 8

Military

MIL-STD-810 Systems MIL-STD-883 Circuit Cards MIL-STD-202 Components

SRS Classical Pyroshock Ballistic Shock

Handling and Free Fall Drop Tests

Drop Surfaces

Concrete Steel Wood Sand

Package or Device

Typical Classical Shock Tests for Electronic Systems

Reference Specification MIL-STD-810F Ground Equipment ISO 16750-3 General Motors GMW 3172 General Motors GMW 3172 Ford Motor RTCA DO-160D (Operational) RTCA DO-160D (Crash Safety)

Amplitude Pulse and Duration Shape ms Sa tooth ms alf Sinems ms ms ms ms alf Sine alf Sine alf Sine Sa tooth Sa tooth

p lses p lses p lses p lses p lses p lse p lse

Quantity a es ir a es ira es a es a es a es a es ir ir ir ir ir

total total total total total total total

Typical Classical Shock Tests for Electronic SystemsIEC 68-2-27Gs Time Wave Components EquipmentLand based ite m s o r ite m s tra n s p o rte y ro a ra il o r a ir in secured shock resistant packages In s ta lle o r tra n p o rte in a s e c r e p o s itio n o n n o rm a l ro a o r ra il e h ic le s o r in tra n s p o rt a irc ra ft

S

S

S tr c t r a l in te rity te s ts o n semiconductors, integrated circuits, microcircuits. S tr c t r a l in te rity te s ts o n semiconductors, integrated circuits, microcircuits.

6

ST

ST

S T

S T

Ite m s in secured packages transported by full cross country vehicles. Items mounted in equipment tranported by or installed in full cross country vehicles or aircraft

Ite m s in secured packages y h e e le vehicles, tra n s p o rte aircraft, merchant ships or light marine craft.

Ite m s in s ta lle o r tra n s p o rte in a secured position in full cross-counry vehicles Ite m s c a rrie 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.

8

ST

S T

ST

S T

e n e ra l h a n lin

an

tra n s p o rt

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 0.5msec 150Gs Long Pulse 30msec 15Gs

Classical Shock Pulses

Advantages

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

Disadvantages

Classical Shock TestsAxis1(g's)Axis2(g's)Axis3(g's) 15 10 5 0 -5 -10 -15 -20 15 10 5 0 -5 -10 -15 10 5 0 -5 -10 -15 0 20 Engine 3.sif - AccelTH@Axis3.RN_2

Engine 3.sif - AccelTH@Axis2.RN_2

Engine 3.sif - AccelTH@Axis1.RN_2

40 Time(secs)

60

80

100

Classical Shock Tests15 10 5 Axis3(g's) 0 -5 -10 -15 -20 0 5 10 Time(secs) 15 20 TmpEdit_0004.sif - AccelTH@Axis3.RN_2

Shock Response SpectrumEnergy Spectral Density

A ug 2 8 , 2 0 0 7 1 6 :0 6 :5 0

Pr e -T r ig g e r : 5 0 ms

H o ldO ff: 0 ms

O mr o n 3 8 7 2 6

C a ptur e 1 0 0 0 mS

6 4 C a ptur e d

1 0 0 G 's , 1 1 ms e c

Acceleration

XAQ1

re uenc

A ug 28, 2007 16:08:50

Pr e -T r igge r : 50 ms

HoldOff: 0 ms

Omr on 38726

C aptur e 1000 mS

80 C aptur e d

100 G's , 11 ms e c

Acce er t on

T r igge r : 10 G (R is ing)

C hanne l: X A Q1,V SS A c c e l,C h3,C h4,C h5,C h6,C h7,C h8,C h9,C h10,C h11,C h12,C h13,C h14,C h15,C h16,C h17,C h18,C h19,C h20,C h21,C h22,C h23,C h24,C h25,C h26,C h27,C h28,C h29,C h30,C h31,C h32 Pos t-C aptur e holdoff half-s ine

Acceleration

XAQ1

me ms

Acce er t on

XAQ1

me m s

QI

PR

QcQQQR

QR

P

QcQQR

VwvU u t sc R QQ

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V U TS PH

QR H

PR H

QcR

T r ig g e r : 1 0 G (R is ing )

C ha nne l: X A Q 1 ,V SS A c c e l,C h3 ,C h4 ,C h5 ,C h6 ,C h7 ,C h8 ,C h9 ,C h1 0 ,C h1 pturh1 ho ldo ff ,C h1 4 ,C h1 5 ,C h1 6 ,C h1 7 ,C h1 8 ,C h1 9 ,C h2 0 ,C h2 1 ,C h2 2 ,C h2 3 ,C h2 4 ,C h2 5 ,C h2 6 ,C h2 7 ,C h2 8 ,C h2 9 ,C h3 0 ,C h3 1 ,C h3 2 Po s t-C a 1 ,C e 2 ,C h1 3 ha lf-s ine

QIH PIHQPH Q QP X YW ` QQR ab QPR

ens t

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Rc Q edQR fR gdQR fR hdQR fR Yx idQR fR 0 y a` pdQR fR b qdQR fR rdQR fR/

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Energy Spectral Density

Shock

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