ASTM D4728 PDF
ASTM D Standard Test Method for Random Vibration Testing of Shipping Containers has been released. It revises and replaces the. This standard is issued under the fixed designation D ; the number immediately 1 This test method is under the jurisdiction of ASTM Committee D10 on. ASTM D Standard Test Method for Random Vibration Testing of Shipping Containers.
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The number of DOF is determined by the analysis bandwidth frequency resolution and total time of the sample determined by frequency resolution and number of averages.
In this way, many product and container resonances are simultaneously excited. When possible, confidence levels may be improved by comparing laboratory test results with actual field shipment effects. In this way, many product and container resonances are simultaneously excited.
When the specimen is not secured to the table, restraining devices should be attached to the vibration table to prevent potential movement of the specimen off the vibration table.
A number in parentheses indicates the year of last reapproval. Link to Active This link will always route to the current Active version of the standard.
ASTM D – 17 Standard Test Method for Random Vibration Testing of Shipping Containers
This table feedback signal is generated by an accelerometer mounted directly to the table. Design modification to one or all of these components may be used to achieve optimum performance in the shipping environment. Creating a Random Vibr Any attempt to do so should be done with caution. Field measurements must be accurately recorded with equipment having adequate frequency response and dynamic range to prevent attenuation or noise contamination of the acceleration energy levels.
It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and determine the applicability of regulatory limitations prior to use. For example, if atm laboratory test does not produce a realistic level of damage, then adjustments should be made. Approximating the actual damage, or lack of damage, experienced in real life may require subjecting the container and its contents to random vibration tests.
Equivalent tests between sine and random, in a general sense, are difficult to establish due to nonlinearities, damping and product response characteristics. Vibration exposure affects the shipping container, its interior packing, means of closure, and contents. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
The instantaneous amplitudes of a random vibration are prescribed by a probability distribution function, the integral of which over a given amplitude range will d478 the probable percentage of time that the amplitude will fall within that Copyright? Very steep slopes require smaller bandwidths to maintain control to 63 dB.
Approximating the actual damage, or lack of damage, experienced in real life may require subjecting the container and its contents to random vibration tests. Refer to Astk D for recommended random vibration tests.
Calibration and Standardization 8. Precision and Bias The controller automatically generates equalized vibration test system drive signals to achieve the desired PSD thus maintaining closed loop control.
Historical Version s – view previous versions of standard. A superscript epsilon e indicates an editorial change since the last revision or reapproval. This test allows analysis of the interaction between these components. Current edition approved Oct.
However, different test aatm may be utilized for each axis depending on the field environment that is to be simulated. They do not purport to accurately describe a speci? Stop the test immediately if a dangerous condition should develop. Two PSD levels that have a ratio of 2. Refer to Practice D for recommended random vibration tests.
This test allows analysis of the interaction between these components. See Appendix X1 and Appendix X2 for related information. 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.
NOTE 2—Random vibration systems typically create a c4728 signal that follows the Gaussian distribution. Power spectral density is the limit of the mean square amplitude in a given rectangular band divided by the bandwidth, as the bandwidth approaches zero. The equalized drive signals automatically compensate for specimen and vibration test system characteristics. Specific safety hazard statements d47288 given in Section 6. Therefore, unrealistic fatigue damage due to resonance buildup is minimized.
These sample test pro? See Appendix X1 and Appendix X2 for related information. For the zstm of this test method, the bandwidth may be considered equivalent to the frequency resolution of a spectrum analysis. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.
If a dummy load is used, an assessment must be made, after the test is completed, as to whether or not the actual test item would have passed or failed. However, different test levels may be utilized for each axis depending on the?
The vibration table shall be supported by a mechanism capable of producing single axis vibration inputs at controlled levels of continuously variable amplitude throughout the desired range of frequencies.