Dynamic Characteristic Analysis of Fuzzy Stochastic Truss Structures Based on Fuzzy Factor Method and Random Factor Method
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摘要: 针对模糊随机桁架结构的动力特性分析,提出了一种新的模糊随机有限元方法．当结构的物理参数和几何尺寸同时具有模糊随机性时，利用模糊因子法和随机因子法建立了结构刚度矩阵和质量矩阵；从结构振动的Rayleigh商表达式出发，利用区间运算推导出结构动力特性模糊随机变量的计算表达式；之后利用随机变量的矩法和代数综合法,推导出结构特征值的数字特征的计算式．通过算例分析了模糊随机桁架结构参数的模糊随机性对其动力特性的影响．该方法的优点是能准确反映结构某一参数的模糊随机性对结构特征值及其数字特征的影响．
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关键词:
- 模糊随机桁架 /
- 模糊因子法 /
- 随机因子法 /
- 动力特性模糊随机变量
Abstract: A new fuzzy stochastic finite element method based on the fuzzy factor method and random factor method is given and the analysis of structural dynamic characteristic for fuzzy stochastic truss structures is presented.Considering the fuzzy randomness of the structural physical parameters and geometric dimensions simultaneously,the structural stiffness and mass matrices were constructed based on the fuzzy factor method and random factor method;from the Rayleigh's quotient of structural vibration,the structural fuzzy random dynamic characteristic was obtained by means of the interval arithmetic;the fuzzy numeric characteristics of dynamic characteristic were then derived by using the random variable's moment function method and algebra synthesis method.Two examples were used to illustrate the validity and rationality of the method given.The advantage of this method is that the effect of the fuzzy randomness of one of the structural parameter on the fuzzy randomness of the dynamic characteristic can be reflected expediently and objectively. -
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