宽带随机振动峰值应力分析与试验研究

考核结构件在宽带随机激励下的强度，需要考察结构的峰值应力响应. 利用随机振动 和正弦振动之间的峰值等效原理，通过正弦振动在共振频率点的应力响应来计算随机振动的 峰值应力. 以某结构件为例，利用有限元分析软件MSC.NASTRAN，对该结构件进行了模态分 析、频响分析、随机振动加速度响应及峰值应力响应分析；同时实施了随机激励下的应力测 试试验. 比较分析与试验的峰值应力，误差在10{\%}以内，表明了该工程分析方法和技术途 径是合理的.

ANALYSIS AND TESTS OF THE PEAK VALUE OF STRESS IN BROADBAND RANDOM VIBRATION

The peak value of stress response is important when the strength of the structure in broadband random vibrations is considered. Based on the peak value equivalent theory of the random vibration and the sinusoidal vibration, the peak value of stress response in a random vibration can be obtained by the stress response at the resonant frequency of the sinusoidal vibration. The modal analysis, frequency response, prediction for the acceleration response and the peak value of stress response of a selected structure in random vibrations are carried out with MSC.NASTRAN. It is shown that the error of the peak value of stress response between analysis and test results is less than 10{\%}; therefore, the method of stress response prediction in random vibrations is reasonable and practical.