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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A factor of 2 or more is normally used for an added safety margin. The test surface shall be guided to fall vertically without rotation or translation in other directions.
Two test methods are outlined, as follows: Government Printing Office,pp. Last previous edition D — awtm A product usually has a different critical velocity change for each direction in which it is tested.
Method A is used when information on drop heights is limited. For example, a component of a product with a natural frequency below 56 Hz can be effectively tested on a shock machine with a 3 ms duration pulse.
ASTM D3332 Foam Test Methods
Method B is used when drop heights are known with great certainty. Common practice is to de? Calculation that assumes the shock pulse to be a perfect geometric? Multidirectional tests are d3332 since most products have different fragilities in different orientations.
ASTM D Standard for Mechanical_百度文库
Link to Active This link will always route to d3323 current Active version of the standard. ASTM D outlines three test methods A-C for determining the fragility of products to be packaged for shipment in the distribution environment.
Acceptable increment size is in? Site design by Softnet.
A sample of the product was subjected to half-sine shock pulses in accordance with Test Method A. For this reason, shocks transmitted by some cushion materials will be less severe than those produced by the trapezoidal-shock pulse test.
The accelerometer is fastened to the carriage in this case, and a rigid mass weighing the same as the product is subjected to a series of shock pulses. If the product is complex, usually some sub-element of the product will fail?
NOTE 4—See shock machine manufacturer recommendations for setting acceleration levels because this procedure is speci? The values awtm in parentheses are for information only.
To avoid inconclusive test results, the critical acceleration test is conducted at velocity changes at least two times the critical velocity change of the product.
It may also be used to improve product ruggedness. The product should be supported by a? A d3332 usually has a different critical acceleration for each direction in which it is tested.
The machine is set to attain a velocity change which exceeds the minimum required to damage the product, but at a very low acceleration level.
If none occurs, the machine is reset for a higher maximum acceleration and the test is repeated at the same drop height.
For example, if a half sine shock pulse waveform is used, a c3332 scalloped critical acceleration line is produced and the test data become meaningless.
A superscript epsilon asttm indicates an editorial change since the last revision or reapproval. A research report5 describes an interlaboratory test program of three types of items in packages for a critical velocity change shock test. For the same reason, waveforms having faired shapes that are not trapezoidal should not be used for this test. Each trapezoidal shock pulse had a faired acceleration level incrementally higher than the previous shock pulse. This is sufficient to characterize and indicate the signi?
This fragility information may be used in designing shipping containers for transporting the aztm. Historical Version d332 – view previous versions of standard. If the component asm frequency is higher, the pulse duration must be shorter. The failure level is then de?
Be certain that the velocity change of subsequent shock pulses is maintained at or above the level determined in 9. This is required to avoid the rounded intersection of the critical velocity change and critical acceleration lines.
Damage can render the product unacceptable because it becomes inoperable or fails to meet performance speci? The accelerometer shall be attached rigidly to the base structure of the product or to the? The repeatability standard deviations were 6. Most products are not affected by this multiplicity of tests. If zero damping is speci?
ASTM D | Rycobel
Therefore, the test in accordance with Test Method B 9. Drop height control shall be provided to permit reproducibility within Two test methods are outlined, as follows: Unit or consumer packages, which are c3332 within an outer container, are considered to be the product for the purposes of these test methods.
Since they are relatively easy to control, shock pulses having a half sine shock waveform are normally used. The damage boundary of a trapezoidal-shock pulse envelops damage boundaries produced by other waveforms. 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.
The peak acceleration of this shock pulse will often exceed Ac.