1、Designation: D3332 99 (Reapproved 2010)Standard Test Methods forMechanical-Shock Fragility of Products, Using ShockMachines1This standard is issued under the fixed designation D3332; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover determination of the shockfragility of products. This fragility information may b
3、e used indesigning shipping containers for transporting the products. Itmay also be used to improve product ruggedness. Unit orconsumer packages, which are transported within an outercontainer, are considered to be the product for the purposes ofthese test methods. Two test methods are outlined, as
4、follows:1.1.1 Test Method A is used first, to determine the productscritical velocity change.1.1.2 Test Method B is used second, to determine theproducts critical acceleration.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalcon
5、versions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practi
6、ces and determine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements, see Section 6.2. Referenced Documents2.1 ASTM Standards:2D996 Terminology of Packaging and Distribution Environ-mentsD2463 Test Method for Drop Impact Resistance of Blow-Molded Thermopl
7、astic ContainersD3580 Test Methods for Vibration (Vertical Linear Motion)Test of ProductsD4332 Practice for Conditioning Containers, Packages, orPackaging Components for TestingD5112 Test Method for Vibration (Horizontal Linear Mo-tion) Test of ProductsE122 Practice for Calculating Sample Size to Es
8、timate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE680 Test Method for Drop Weight Impact Sensitivity OfSolid-Phase Hazardous Materials3. Terminology3.1 DefinitionsGeneral definitions for packing and distri-bution are found in Terminology D996.3.2 Definitions of Ter
9、ms Specific to This Standard:3.2.1 acceleration of gravity (g)386.1 in./s2(9.806 m/s2).3.2.2 critical acceleration (Ac)the maximum-faired accel-eration level for a minimum velocity change of 1.57 DVc(see9.3), above which product failure (or damage) occurs. Aproduct usually has a different critical a
10、cceleration for eachdirection in which it is tested.3.2.3 critical velocity change (Vc)the velocity change (see9.2) below which product failure is unaffected by shock-pulsemaximum-faired acceleration or waveform. A product usuallyhas a different critical velocity change for each direction inwhich it
11、 is tested.3.2.4 damageproduct failure that occurs during a shocktest. Damage can render the product unacceptable because itbecomes inoperable or fails to meet performance specificationswhen its appearance is unacceptably altered, or some combi-nation of these failure modes occurs.3.2.5 damage bound
12、arySee Annex A3.3.2.6 fairingThe graphical smoothing of the amplitude ofa recorded pulse still containing high frequency componentseven though electronic filtering may have been performed.This amplitude is used to evaluate the basic recorded pulsefeatures with respect to the specified pulse. (see Fi
13、gs. A1.1 andA2.1)1These test methods are under the jurisdiction of ASTM Committee D10 onPackaging and are the direct responsibility of Subcommittee D10.15 on FragilityAssessment.Current edition approved Jan. 1, 2010. Published January 2010. Originallyapproved in 1988. Last previous edition approved
14、in 2004 as D3332 99(2004).DOI: 10.1520/D3332-99R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright
15、 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.7 shock pulse programmera device used to control theparameters of the acceleration versus time shock pulse gener-ated by a shock test machine.3.2.8 shock test machine drop heightthe distance
16、throughwhich the carriage of the shock test machine falls beforestriking the shock pulse programmer.4. Significance and Use4.1 These test methods are intended to provide the user withdata on product shock fragility that can be used in choosingoptimum-cushioning materials for shipping containers or f
17、orproduct design modification.5. Apparatus5.1 Shock Test Machine:5.1.1 The machine shall consist of a flat horizontal testsurface (carriage) of sufficient strength and rigidity to remainflat and horizontal under the stresses developed during the test.The test surface shall be guided to fall vertical
18、ly withoutrotation or translation in other directions.5.1.2 The machine shall incorporate sufficient carriage dropheight to produce the shock pulses given in 9.2 and 9.3. Dropheight control shall be provided to permit reproducibilitywithin 60.25 in. (66 mm).5.1.3 The machine shall be equipped to pro
19、duce shockpulses at the carriage as specified in 9.2 and 9.3.5.1.4 Means shall be provided to arrest the motion of thecarriage after impact to prevent secondary shock.5.2 Instrumentation:5.2.1 Acceleration An accelerometer, signal conditioner,and data storage apparatus are required to record acceler
20、ation-time histories. The accelerometer shall be attached rigidly tothe base structure of the product or to the fixture, at or near apoint at which the fixture is fastened to the carriage. If thefixture is sufficiently rigid to not distort the shock pulseimparted to the product, the accelerometer ma
21、y be mounted onthe carriage. In some cases, when a product contains heavyresiliently supported masses that will distort the shock pulsesseverely, it may be necessary to precalibrate the shock ma-chine. The accelerometer is fastened to the carriage in this case,and a rigid mass weighing the same as t
22、he product is subjectedto a series of shock pulses. The instrumentation system shallhave sufficient response to permit measurements in the follow-ing ranges.5.2.1.1 Test Method A 5 Hz or less to at least 1000 Hz.5.2.1.2 Test Method B 1 Hz or less to at least 330 Hz.5.2.1.3 AccuracyReading to be with
23、in 65 % of the actualvalue.5.2.1.4 Cross-Axis SensitivityLess than 5 % of the actualvalue.5.2.2 VelocityInstrumentation to measure the velocitychange of the shock table is required. This may be a device thatintegrates the area electronically under the shock pulse wave-form. Alternatively, it can be
24、measured by photodiode-typedevices that measure shock table impact and rebound velocity.Calculation that assumes the shock pulse to be a perfectgeometric figure is usually grossly inaccurate and should not beused.6. Precautions6.1 These test methods may produce severe mechanicalresponses in the test
25、 specimen. Operating personnel musttherefore remain alert to potential hazards and take necessarysafety precautions. The test area should be cleared prior to eachimpact. The testing of hazardous material or products mayrequire special precautions that must be observed. Safetyequipment may be require
26、d, and its use must be understoodbefore starting the test.7. Sampling7.1 Sampling procedures and the number of test specimensdepend on the specific purposes and needs of the testing.Sample size determination based on Practice E122 or otherestablished statistical procedures is recommended.8. Conditio
27、ning8.1 If temperature and humidity conditioning is required forthe product being tested, refer to Practice D4332 for standardconditioning procedures. Unless otherwise specified, conductall tests with the same conditions prevailing.9. Procedure9.1 Mount the product to be tested on the carriage of th
28、eshock test machine. The product should be supported by afixture similar in shape and configuration to the cushion thatwill support the product in its shipping container. The fixtureshould be as rigid as possible so as not to distort the shockpulse imparted to the product. Fasten the fixture and pro
29、ductsecurely to the carriage so that it will not leave the surface ofthe carriage during the shock test.NOTE 1The points at which the fixture supports the product are veryimportant because the dynamic response of the product is influencedstrongly by the location of these support pointsNOTE 2If the o
30、rientation of the product can change during handlingimpacts, a test may be required for each of the directions in which theinput shock can occur. Multidirectional tests are recommended since mostproducts have different fragilities in different orientations.9.2 Test Method ACritical Velocity Change S
31、hock Test:9.2.1 ScopeThis test method is used to determine thecritical velocity change ( Vc) portion of the damage boundaryplot of a product.9.2.1.1 To ensure that the components of a product onlyrespond to the velocity change of the pulse, a shock pulsehaving any waveform and a duration (Tp) not lo
32、nger than 3 msshould be used to perform this test. Pulse durations as short as0.5 ms may be required when testing small, very rigid products(see Note 3). Shock pulse waveform is not limited since thecritical velocity portion of the damage boundary is unaffectedby shock pulse shape. Since they are re
33、latively easy to control,shock pulses having a half sine shock waveform are normallyused.NOTE 3In general: Tp# 167 / fcwhere:Tp= maximum shock test machine pulse duration in ms, andfc= component natural frequency in Hz.For example, a component of a product with a natural frequency below56 Hz can be
34、effectively tested on a shock machine witha3msdurationD3332 99 (2010)2pulse. If the component natural frequency is higher, the pulse durationmust be shorter. A 2 ms duration pulse can be used on a component witha natural frequency up to 83 Hz.9.2.2 Procedure:9.2.2.1 Set the shock test machine so tha
35、t the shock pulseproduced has a velocity change below the anticipated criticalvelocity change of the product.9.2.2.2 Perform one shock test.9.2.2.3 Examine or functionally test the product, or do both,to determine whether damage due to shock has occurred.9.2.2.4 If no damage has occurred, set the sh
36、ock testmachine for a higher velocity change and repeat the shock test.Acceptable increment size is influenced strongly by the productbeing tested. For example, an increment of 5 in./s (0.13 m/s)may be appropriate for most products but unacceptable forhigh-value products.9.2.2.5 Repeat 9.2.2.2-9.2.2
37、.4, with incrementally increas-ing velocity change, until product damage occurs. This point isshown as Test No. 7 in Fig. A3.1.9.2.2.6 Common practice is to define the critical velocitychange (Vc) as the midpoint between the last successful test andthe test that produced failure. Depending on the pu
38、rpose of thetest, use of the last successful test point before failure may beconsidered as a more conservative estimate of (Vc).9.3 Test Method BCritical Acceleration Shock Test:9.3.1 ScopeThis test method is used to determine thecritical acceleration ( Ac) portion of the damage boundary plotof a pr
39、oduct.9.3.1.1 When the critical acceleration of a product is known,package cushioning materials can be chosen to protect it.9.3.1.2 If no cushioning materials are to be used in thepackage, it may be unnecessary to perform this test. Only thecritical velocity change test may suffice in this case.9.3.
40、1.3 Trapezoidal shock pulses are normally used toperform this test. Although a true square wave shock pulse ismost desirable in theory, it is not possible to obtain infinitelyshort rise and fall times. On the basis of much testingexperience, it has been determined that rise and fall times (seeFig. A
41、2.1) of 1.8 ms, or less, are required. Longer rise and falltimes cause the critical acceleration line of the damageboundary curve to deviate from the horizontal, introducingerrors into the test results. For the same reason, waveformshaving faired shapes that are not trapezoidal should not be usedfor
42、 this test. Their use would cause the critical acceleration lineof the damage boundary curve to vary widely as a function ofvelocity change. For example, if a half sine shock pulsewaveform is used, a deeply scalloped critical acceleration lineis produced and the test data become meaningless.9.3.2 Pr
43、ocedure:9.3.2.1 Set the shock test machine so that it will produce atrapezoidal shock pulse having a velocity change of at least1.57 times as great as the critical velocity change determined inTest Method A (9.2). A factor of 2 or more is normally used foran added safety margin. This is required to
44、avoid the roundedintersection of the critical velocity change and critical accel-eration lines. Maximum-faired acceleration level of the firstshock pulse should be below the anticipated failure level of theproduct.9.3.2.2 Perform one shock test.9.3.2.3 Examine the recorded shock pulse to be certain
45、thedesired maximum-faired acceleration and velocity change wereobtained.9.3.2.4 Examine or functionally test the product, or do both,to determine whether damage due to shock has occurred.9.3.2.5 If no damage has occurred, set the shock testmachine for a higher maximum-faired acceleration level. Bece
46、rtain that the velocity change of subsequent shock pulses ismaintained at or above the level determined in 9.3.2.1. Accept-able increment size is influenced strongly by the product beingtested. For example, an increment of 5 g may be appropriate formost products but unacceptable for high-value produ
47、cts.NOTE 4See shock machine manufacturer recommendations for set-ting acceleration levels because this procedure is specific to the type ofprogrammer.9.3.2.6 Repeat 9.3.2.2-9.3.2.5, with incrementally increas-ing maximum-faired acceleration, until product damage oc-curs. This point is shown as Test
48、No. 14 in Fig. A3.1. Commonpractice is to define the critical acceleration (Ac)asthemidpoint between the last successful test and the test thatproduced failure. Depending on the purpose of the test, use ofthe last successful test point before failure may be consideredas a more conservative estimate
49、of (Ac).10. Report10.1 Report the following information:10.1.1 Reference to these test methods, noting any devia-tions from the test method.10.1.2 Complete identification of the product being tested,including type, manufacturers code numbers, general descrip-tion of configuration, and its pretest condition.10.1.3 Method of mounting the product on the carriage ofthe shock test machine.10.1.4 Type of instrumentation used and critical settingsthereof.10.1.5 Recordings of the shock pulses that caused productdamage.10.1.6 Record of shock test machine drop height
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