1、Designation: D 3332 99 (Reapproved 2004)Standard Test Methods forMechanical-Shock Fragility of Products, Using ShockMachines1This standard is issued under the fixed designation D 3332; 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 (e) 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 ma
3、y be 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,
4、as 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 either inch-pound or SI units are tobe regarded as the standard. The values given in parentheses
5、are for information only.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 practices and determine the applica-bility of regulatory limitations pri
6、or to use. For specificprecautionary statements, see Section 6.2. Referenced Documents2.1 ASTM Standards:2D 996 Terminology of Packaging and Distribution Environ-mentsD 2463 Test Method for Drop Impact Resistance of Blow-Molded Thermoplastic ContainersD 3580 Test Method for Vibration (Vertical Linea
7、r Motion)Test of ProductsD 4332 Practice for Conditioning Containers, Packages, orPackage Components for TestingD 5112 Test Method for Vibration (Horizontal Linear Sinu-soidal Motion) Test of ProductsE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the Average
8、 for Charac-teristic of a Lot or ProcessE 680 Test Method for Drop Weight Impact Sensitivity ofSolid-Phase Hazardous Materials3. Terminology3.1 DefinitionsGeneral definitions for packing and distri-bution are found in Terminology D 996.3.2 Definitions of Terms Specific to This Standard:3.2.1 acceler
9、ation 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 acceleration for eachdirection in which it
10、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 is tested.3.2.4 damageproduct failure tha
11、t 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 boundarySee Annex A3.3.2.6 fairingThe graphical
12、 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 Figs. A1.1 andA2.1)3.2.7 shock pulse program
13、mera device used to control theparameters of the acceleration versus time shock pulse gener-ated by a shock test machine.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 ap
14、proved Oct. 1, 2004. Published October 2004. Originallyapproved in 1988. Last previous edition approved in 1999 as D 3332 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information,
15、refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.8 shock test machine drop heightthe distance throughwhich the carriage of the shock test machine falls beforestriking
16、 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 forproduct design modification.5. Apparatus5.1 Shock Test Machine:5.1.1 T
17、he 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 vertically withoutrotation or translation in other directions.5.1.2 The machine
18、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 produce shockpulses at the carriage as specified in 9.2 and 9.3.5.1.4 Means
19、 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 acceleration-time histories. The accelerometer shall be attached rigidly tothe
20、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 may be mounted onthe carriage. In some cases, when a product contains heav
21、yresiliently 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 the product is subjectedto a series of shock pulses. The instrumentation
22、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 within 65 % of the actualvalue.5.2.1.4 Cross-Axis SensitivityLess than 5 % o
23、f 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 measured by photodiode-typedevices that measure shock table impact and r
24、ebound 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 specimen. Operating personnel musttherefore remain alert to potential h
25、azards 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 required, and its use must be understoodbefore starting the test.7. Sampling7.1
26、 Sampling procedures and the number of test specimensdepend on the specific purposes and needs of the testing.Sample size determination based on Practice E 122 or otherestablished statistical procedures is recommended.8. Conditioning8.1 If temperature and humidity conditioning is required forthe pro
27、duct being tested, refer to Practice D 4332 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 theshock test machine. The product should be supported by afixture simil
28、ar 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 productsecurely to the carriage so that it will not leave the surface oft
29、he 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 orientation of the product can change during handlingimpacts, a test ma
30、y 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 Shock Test:9.2.1 ScopeThis test method is used to determine thecritical
31、 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 longer than 3 msshould be used to perform this test. Pulse durations as
32、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 relatively easy to control,shock pulses having a half sine shock wavefor
33、m 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 effectively tested on a shock machine witha3msdurationpulse. If the co
34、mponent 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.D 3332 99 (2004)29.2.2 Procedure:9.2.2.1 Set the shock test machine so that the shock pulseproduced has a velocity change below the anticipated
35、 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 shock testmachine for a higher velocity change and repeat the shock tes
36、t.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 9.2.2.2-9.2.2.4, with incrementally increas-ing velocity change, until product dam
37、age 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 purpose of thetest, use of the last successful test point before failur
38、e 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 product.9.3.1.1 When the critical acceleration of a product is known,pa
39、ckage 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.9.3.1.3 Trapezoidal shock pulses are normally used toperform this test. A
40、lthough 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. A2.1) of 1.8 ms, or less, are required. Longer rise and falltimes caus
41、e 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 this test. Their use would cause the critical acceleration lineof th
42、e 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 Procedure:9.3.2.1 Set the shock test machine so that it will produce at
43、rapezoidal 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 avoid the roundedintersection of the critical velocity change and cri
44、tical 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 thedesired maximum-faired acceleration and velocity change wereobtain
45、ed.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. Becertain that the velocity change of subsequent shock pulses ismaintaine
46、d 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 products.NOTE 4See shock machine manufacturer recommendations for set-ting
47、 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 No. 14 in Fig. A3.1. Commonpractice is to define the critical acceler
48、ation (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 of (Ac).10. Report10.1 Report the following information:10.1.1 Refere
49、nce 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 for eachshock pulse that caused product damage.10.1.7 Record of damag
