Spectral stochastic finite element vibration analysis of fiber-reinforced composites with random fiber orientation
Spectral stochastic finite element vibration analysis of fiber-reinforced composites with random fiber orientation
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DOI：
10.1016/j.compstruct.2016.02.069
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发表时间：
2016-06-10
影响因子：
6.3
通讯作者：
Sepahvand, K.
中科院分区：
文献类型：
--
作者：
Sepahvand, K.
纤维增强复合材料由于制造公差而表现出随机的纤维取向。本文对长纤维增强复合材料在纤维取向不确定性情况下的振动行为进行了数值研究。建立了基于一阶剪切变形的层合板理论的基本随机本构方程。假设每个方向都表现出与标称平均值不同的空间和随机变化。这些导致局部变化的机械性能，如结构刚度和质量矩阵，因此，在结构响应。有限元公式利用频谱随机离散的意义上说，随机纤维的方向近似截断Karhunen-Loeve展开。扩展提供了一个框架来捕获空间和随机变化。采用具有未知确定性系数的广义多项式混沌来描述结构响应。使用概率配置点估计系数，其中任何确定性的内部代码或商业有限元软件包可以被视为用于结构建模和分析的黑盒。数值算例研究了纤维取向的不确定性对12层复合材料矩形板固有频率和振型的影响，该矩形板的名义取向为[0/90]（s）。(C)2016爱思唯尔有限公司版权所有。
Fiber-reinforced composites exhibit random fiber orientations due to the manufacturing tolerances. The present study concerns with a numerical investigation of the vibrational behavior of the long fiber-reinforced composites under uncertainty in fiber orientations. The basic constitutive equations of laminate theory based on the first-order shear deformation are developed in stochastic form. It is assumed that each ply-orientation exhibits individual spatial and random variations from the nominal mean value. These lead to local variations in mechanical properties such as structural stiffness and mass matrices and, accordingly, in structural responses. The finite element formulation utilizes the spectral stochastic discretization in the sense that the random fiber orientations are approximated by a truncated Karhunen-Loeve expansion. The expansion provides a framework to capture the spatial and random variations. The generalized polynomial chaos with unknown deterministic coefficients is employed to represent the structural responses. The coefficients are estimated using probabilistic collocation points where any deterministic in-house code or commercial FEM package can be treated as a black-box for the modeling and analysis of structure. A numerical case study is used to illustrate the features of the method, where impact of the uncertainty in fiber orientations on the natural frequencies and mode shapes of a 12 plies rectangular composite plate with nominal orientation of [0/90](s) is investigated. (C) 2016 Elsevier Ltd. All rights reserved.