This standard is issued under the fixed designation D ; the 1 These test methods are under the jurisdiction of ASTM Committee D on. ASTM D Standard Test Methods for Mechanical-Shock Fragility of Products , Using Shock Machines. Shock Machine Testing. Shock testing was performed on a shock machine that is in compliance with the following standard: ASTM D −
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Current edition approved April 10, For a given product, the interrelation of these three parameters is shown by damage boundary, as plotted in Fig. Since they are relatively easy to control, shock pulses having a half sine shock waveform are normally used. For the same reason, waveforms having faired shapes that are not trapezoidal should qstm be used for this test.
A product usually has a different critical acceleration for each direction in which it is tested. The test surface shall be guided to fall vertically without rotation or translation in other directions.
A product usually has a different critical velocity change for each direction in which it is tested. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Last previous edition D — If none occurs, the machine is reset for a higher maximum acceleration and the test is repeated at the same drop height. Shock Response Spectrum SRS analysis can provide a tool for safely reducing the amount of conservatism. A research report5 describes an interlaboratory test program of three types of items in packages for a critical velocity change shock test. Method B is used when drop heights are known with great certainty. That is, it may be possible to design the cushion to transmit a somewhat higher acceleration yet still not cause damage to the product.
Other items may have more or less variability. Although a true square wave shock pulse is most desirable in theory, it is not possible to obtain in?
Longer rise and fall times cause the critical acceleration line of the damage boundary curve to deviate from the horizontal, introducing errors into the test results.
Their use would cause the critical acceleration line of the damage boundary curve to vary widely as a function of velocity change.
ASTM D3332 Foam Test Methods
This amplitude is used to evaluate the basic recorded pulse features with respect to the speci? This point is shown as Test No.
Failure occurred in the seventh test, establishing the vertical critical velocity change line midway between the sixth astmm seventh test levels see 9.
D Terminology of Packaging and Distribution Environments. Quality Foam can fabricate our foams to your exact specifications, whether working from our own in-house design or customer-supplied drawings. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
Precision and Bias NOTE 4—See shock machine manufacturer recommendations for setting acceleration levels because this procedure is speci?
ASTM D Foam Test Methods
It will fail only when it is subjected to asmt higher level shocks. For example, an increment of 5 g may be appropriate for most products but unacceptable for high-value products. The test area should be cleared prior to each impact.
If it passes, the specimen is tested at a shock level that is incrementally higher. Multiple samples of such a product are usually tested. In some cases, when a product contains heavy resiliently supported masses that will distort the shock pulses severely, it may be necessary to precalibrate the shock machine.
This procedure is less accurate than that described in A4. An SRS plot is a graph of the absolute value of the maximum response accelerations of each spring-mass system, plotted at their various asstm frequencies. As more product samples become available, the test results should be re? However, some products will fail prematurely due to cumulative effects. It is the responsibility asgm the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
This is required to avoid the rounded intersection of the critical velocity change and critical acceleration lines. Method A is used when information on drop heights is limited. None will be more severe than those produced by the trapezoidal shock pulse.
For example, if a half sine shock pulse waveform is used, a deeply scalloped critical acceleration line is produced and the test data become meaningless. Each trapezoidal shock pulse had a faired acceleration level incrementally higher than the previous shock pulse.
Depending on the purpose of the test, use of the last successful test point before failure may be considered as a more conservative estimate of Ac. This is because of the differences in pulse shape and characteristics between the fragility test and actual package cushion performance. A factor of 2 or more is normally used for an added safety margin.
This fragility information may be used in designing shipping containers for transporting the products. Be certain that the velocity change of subsequent shock pulses is maintained at or above the level determined in 9.
The maximum acceleration at which product damage first occurs is the fragility of the d332 in the direction tested.
For example, an increment of 5 in. If the product is complex, usually some sub-element of the product will fail? Common practice is to de? The test data will have to be corrected if x3332
Acceptable increment size is in? Depending on the purpose of the test, use of the last successful test point before failure may be considered as a more conservative estimate of Vc.
NOTE 1—The points at which the?