ASTM D 3580-95 Standard Test Methods for Vibration (Vertical Linear Motion) Test of Products
产品振动试验的标准测试方法滚滚红尘歌词
1. Scope
1.1 The test methods cover the determination of resonances of unpackaged products and components of unpackaged products by means of vertical linear motion at the surface on which the product is mounted for test. Two alternate test methods are prented:
Test Method A-Resonance Search Using Sinusoidal Vibration, and
Test Method B-Resonance Search Using Random Vibration.
1.2 This information may be ud to examine the respon of products to vibration for product design purpos, or for the design of a container or interior package that will minimize transportation vibration inputs at the critical frequencies, when the products r
esonances are within the expected transportation environment frequency range. Since vibration damage is most likely to occur at product resonant frequencies, the resonances may be thought of as potential product fragility points.
1.3 Information obtained from the optional dwell test methods may be ud to asss the fatigue characteristics of the resonating components and for product modification. This may become necessary if the respon of a product would require design of an impractical or excessively costly shipping container.
1.4 The test methods do not necessarily simulate the vibration effects that the product will encounter in its operational or in-u environment. Other, more suitable test procedures should be ud for this purpo.
1.5 Test levels given in the test methods reprent the correlation of the best information currently available from rearch investigation and from experience in the u of the test methods. If more applicable or accurate data are available, they should be substituted. 幻镜诺德琳
2. Referenced Documents
2.1 ASTM Standards:
D 996 Terminology of Packaging and Distribution Environments
D 4332 Practice for Conditioning Containers, Packages, or Package Components for Testing
D4728 Test Method for Random Vibration Testing of Shipping Containers
E 122 Practice for Choice of Sample Size to Estimate the Average Quality of a Lot or Process
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2.2 Military Standard: 微信红包发错了怎么撤回
MIL-STD 810, Method 514 Vibration
3. Terminology
3.1 Definitions- 得意反义词For definitions of terms ud in the test methods, e Terminology D 996.
3.2 Descriptions of Terms Specific to This Standard:
3.2.1 decade- the interval of two frequencies having a basic frequency ratio of 10 (1 decade = 3.322 octaves).
3.2.2 decibel (dB)- a logarithmic expression of the relative values of two quantities. For relative power measurements, the dB value equals 10 times the ba-l0 logarithm of the ratio of the two quantities, that is, dB = 10 {Pl/P2}.
3.2.3 mean-square- the time average of the square of the function.
3.2.4 octave-the interval of two frequencies having a basic frequency ratio of 2 (1 octave = 0.301 decade).
3.2.5 overall g rms-the square root of the integral of power spectral density over the total frequency range.
3.2.6 power spectral density (PSD)-a term ud to quantify the intensity of random vibration in terms of mean-square acceleration per unit of frequency. The units are g 2 /Hz (g 2 /cycles/s). Power spectral density is the limiting mean square value in a given rectangular bandwidth divided by the bandwidth, as the bandwidth approaches zero.
3.2. 7 random vibration- oscillatory motion which contains no periodic or quasiperiodic constituent.
3.2.8 random vibration magnitude- the root-mean- square of the power spectral density value. 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.
3.2.9 resonance- for a system undergoing forced vibration, the frequency at which any change of the exciting frequency in the vicinity of the exciting frequency, caus a decrea in the respon of the system.
3.2.10 root-mean-square (rms)- the square root of the mean-square value. In the exclusive ca of a sine wave, the rms value is 0.707 times the peak.
3.2.11 sinusoidal vibration- periodic motion who acceleration versus time waveform has the general shape of a sine curve, that is, y = sine 希望图片x
激发的意思
3.2.12 sinusoidal vibration amplitude- the maximum value of a sinusoidal quantity. By convention, acceleration is typically specified in terms of zero-to-peak amplitude, while displacement is specified in terms of peak-to-peak amplitude.
3.2.13 汤圆馅transmissibility- the ratio of the measured acceleration amplitude at a point of interest in the product to the measured input acceleration amplitude of the test surface of the apparatus.
