The test standard focuses on finding the resonances of unpackaged products and components of unpackaged products. ASTM-D uses vertical linear motion at the surface on which the product is mounted to find the resonance. There are two alternate test methods. It is important to note that the two separate test methods are not equivalent. Different results may be produced with each method.
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Scope 1. Since vibration damage is most likely to occur at product resonant frequencies, these resonances may be thought of as potential product fragility points. This may become necessary if the response of a product would require design of an impractical or excessively costly shipping container.
Other, more suitable test procedures should be used for this purpose. If more applicable or accurate data are available, they should be substituted. Referenced Documents 2. Terminology 3. Power spectral density is the limiting mean square value in a given rectangular bandwidth divided by the bandwidth, as the bandwidth approaches zero.
The instantaneous magnitudes of random vibration are not prescribed for any given instant in time, but instead are prescribed by a probability distribution function, the integral of which over a given magnitude range will give the probable percentage of the time that the magnitude will fall within that range.
In the exclusive case of a sine wave, the rms value is 0. By convention, acceleration is typically specified in terms of zero-to-peak amplitude, while displacement is specified in terms of peak-to-peak amplitude.
Significance 4. Significance and Use 4. The determination of the resonant frequencies of the product may aid the packaging designer in determining the proper packaging system to provide adequate protection for the product, as well as providing an understanding of the complex interactions between the components of the product as they relate to expected transportation vibration inputs.
Apparatus 5. The test surface shall be driven to move only in vertical linear motion throughout the desired range of amplitudes and frequencies. The mounting devices shall not have significant resonances in the test frequency range. They shall rigidly mount the product in a manner similar to the way in which it will be supported in its shipping container.
Relative motion between the test surface and the specimen mounting interface shall not be permitted. A stroboscope or video system may be beneficial for visual examination of the specimen under test. Hazards 6. Therefore, the means used to fasten the product to the test surface must be of sufficient strength to keep it adequately secured.
Operating personnel shall remain alert to potential hazards and take necessary precautions for their safety. Stop the test method immediately if a dangerous condition should develop. Sampling 7. Whenever sufficient products are available, five or more replicate samples should be tested to improve the statistical reliability of the data obtained see practice E Test Specimens 8.
Sensor s may be applied as appropriate to measure data points of interest with the minimum possible alteration of the test specimen. Parts and surfaces of the specimen may be marked for identification and reference. When necessary to observe interior components of the product during tests, holes may be cut in noncritical area or noncritical panels may be removed. Conditioning 9. Procedure Caution is necessary to avoid excessive pressure or mounting methods that could influence the characteristics of the product.
Experience has shown that most individual transportation environments contain frequencies ranging from 3 Hz to Hz. Acceleration levels sufficient to excite resonance normally range from 0. Starting at 3 Hz, vary the frequency of vibration at a continuous logarithmic rate of 0.
Record any resonant responses of the product, repeat the cycle if necessary. It is recommended that tests be initiated at least 6 dB below full level and incremented in one or more subsequent steps to full test level. This time is dependent upon the characteristics of the vibration test machine and control system, the setup, and the weight and characteristics of the test specimen. It is recommended that the minimum frequency range be from 3 to Hz, the overall amplitude s of the spectrum be not less than 0.
Record any resonant responses of the product. Mount the accelerometer to either the top or bottom of the test surface, as close to the test item as possible, or in a location which produces data representative of table motion. Use a stroboscope; sensors and readouts; and visual, auditory, or other means as applicable to determine these resonances.
Any resonances with transmissibilities of 2 or greater may be considered significant. For sine testing, the frequency sweep may be interrupted or reversed if necessary for short time periods in order to properly identify a resonating component. For sine testing, if different frequencies are recorded for each resonating component on the upsweep as compared to the downsweep a typical situation , record both frequencies and the corresponding sweep direction.
Dwell time, acceleration level, and damage criteria are to be specified by the user. Adjust the frequency of the vibration as necessary to maintain resonance. Test duration, random spectrum, and damage criteria are to be specified by the user. For spectrum examples, see
ASTM D 3580 – 95 pdf free download
Historical Version s - view previous versions of standard. More D The determination of the resonant frequencies of the product may aid the packaging designer in determining the proper packaging system to provide adequate protection for the product, as well as providing an understanding of the complex interactions between the components of the product as they relate to expected transportation vibration inputs. Two alternate test methods are presented:.