复合材料薄壁梁几何非线性分析

根据复合材料薄壁梁变形的特点,假设截面有面外翘曲,应变沿薄壁厚度方向 呈二次曲线形式变化,采用9节点平面单元模拟复杂薄壁截面,用27节点体单元模拟面外翘 曲变形.在Hamilton原理基础上,采用非线性有限元理论,用T.L.法,将位移等状态量写成 增量形式后,推导出了任意复杂截面薄壁复合材料梁计入剪切翘曲大变形分析的几何刚度矩 阵,建立了一个新的任意复合材料薄壁截面梁几何非线性分析模型,并进行了算例验证.算 例表明,建立的模型正确,能够进行复合材料薄壁梁几何非线性分析;截面翘曲对复合 材料梁的变形影响明显;与相关文献做比较,说明了模型的优越性. 

Geometry nonlinear analysis of composite thin walled beams

A new geometry nonlinear finite element model for composite thin walled beams has been developed based on the complex deformation characteristic of the composite thin walled beams.Supposed the strain quadratic varies along the thin-walled,introducing the complex cross-section of beam was simulated by 9-node plane element and the out-of-plane warping displacement was simulated by 27-node solid element.Based on the Hamilton principle,nonlinear finite element theory and the Total Lagrange formulation,the geometry stiffness matrix was formed.The analytical model is proved correct through several examples.The model can be used in analysis of thin-walled composite beams,the warping deformation has evidently affected on composite thin walled beams,compared with related literatures numerical results,the advantage of this model has been showed.