弹性-粘弹性复合结构系统的随机响应分析
THE RANDOM RESPONSE ANALYSIS OF ELASTIC-VISCOELASTIC COMBINED SYSTEMS
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摘要: 本文建立在随机振动时域复模态分析的基础上,利用扩阶状态变量,将弹性-粘弹性复合结构系统的微分积分动力学方程变换成常规的状态方程,提出了一种分析弹性-粘弹性复合结构系统随机响应的方法,得到了弹性-粘弹性复合结构系统在平稳随机激励下响应相关函数矩阵的表达式,并对典型的平稳随机激励(平稳白噪声激励及平稳滤过白噪声激励)情形,进行了分析,得到了典型平稳随机激励下,弹性-粘弹性复合结构系统响应相关函数矩阵的复代数解析表达式。所提分析方法简便、易用,无论单自由度系统或多自由度系统均可适用。本文方法为粘弹性系统的随机响应分析提供了一条途径。Abstract: This paper deals with the random response of elastic-viscoelastic combined systems. A method is proposed on the basis of the complex analysis in the time domain, in which the differential and integral dynamic equation of an elastic-viscoelastic combined system is transformed into an ordinary state equation. The covariance matrices of random responses of elastic-viscoelastic systems under stationary random excitations are obtained. The characteristics of the systems under typical stationary random excitations are investigated and complex algebraic expressions of covariance matrices are given. It is shown that the present method is simple and widely applicable.