To avoid over test in triaxial vibration tests on products,the triaxial load spectrum clipping was introduced based on the equivalence of the maximum response stress in triaxial vibration that in successive uniaxial vibrations using the uniaxial vibration testing standard as a benchmark.The relationship between the excitation and response rms values of a linear system under random vibration was deduced and the ratio n of maximum equivalent stress in uniaxial vibration to that in triaxial vibration was adopted as a clipping coefficient for the rms value of triaxial vibration load spectrum.While doing the clipping,the load spectrum sweep range,the corner frequency value and the slope N of oblique line segment in the load spectrum were kept unchanged.Then,the spectrum values at the straight section of load spectrum were figured out according to the rms value calculation formula for trapezoid spectrum so as to get a triaxial load spectrum that meets the stress equivalence between triaxial and uniaxial random vibrations.Through the clipping on the triaxial load spectrum of a certain typical missile compartment and contrasting the triaxial vibration responses after load spectrum clipping with the uniaxial vibration responses before clipping,the validity and accuracy of the method were verified.
王海东 1， 仇原鹰 2， 周东亮 2，周磊 2,李伟明 1. 一种基于三轴与单轴随机振动最大应力等效的载荷裁剪方法[J]. 振动与冲击, 2017, 36(6): 86-90.
WANG Haidong 1，QIU Yuanying2，ZHOU Dongliang2,ZHOU Lei2,LI Weiming1. Load clipping method based on the maximum stress equivalence between triaxial and uniaxial random vibration. JOURNAL OF VIBRATION AND SHOCK, 2017, 36(6): 86-90.
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