非平稳随机摄动分析中的久期项效应

On the Secular Terms in Random Perturbation Analysis

在非平稳随机响应分析中 ,如果结构参数发生变异 ,由于久期项的存在而使通常的摄动法是否可用一直是有疑问的 ,该文研究得出如果结构的阻尼比不是极小 (在 0 .0 1以上即可 ) ,则参数发生中等以下强度的变异时(变异系数在 10 %之内 ) ,一阶或二阶摄动法都可以较好地近似精确解。

For the non stationary random response analysis of structures with uncertain structural parameters, the applicability of the conventional perturbation scheme has long been questionable because of the existence of the secular terms. For damped structures, the present article shows that if the coefficients of the variation of the structural parameters (stiffiness, mass, or damping ratio) are under 10%, the conventional perturbation scheme will give acceptable approximation to exact solutions.