随机结构动力分析的扩阶系统方法

本文发展了一类用于随机结构系统动力分析的扩阶系统方法。基于随机空间的正交展开理论,文中推导给出了扩阶系统动力方程的一般公式。这组公式可以适用于同时具有随机质量、随机阻尼、随机刚度参数的多自由度动力系统。通过引入虚拟结构的概念,文中建议了形成扩阶系统动力矩阵的有限元方法。通过对比算例分析,证实了扩阶系统方法的可行性与可靠性。最后,讨论了一个很重要现象：随机系统均值反应与相应均值参数系统反应之间的差异并指出了此差异的意义。

AN EXPANDED ORDER SYSTEM METHOD FOR THE DYNAMIC ANALYSIS OF STOCHASTIC STRUCTURES

By applying an orthogonal expansion technique in random space,a general formula for an expanded order system is established. This formula can be used for various multi-degreeoffreedom stochastic structural systems which possess random mass, damping and stiffness parameters. For the continuous random field, a two-step method is suggested to convert it into an expression of independent random variables.A subjunctive structure method is employed to form a basic matrix for the expanded order system.The proposed method is validated through an analysis of simulated data. Finally,the difference between the mean response of a stochastic system and the response of the corresponding "mean parameter System" is discussed.