复合材料层板层间应力的非线性有限元分析

NONLINEAR FINITE ELEMENT ANALYSIS OF INTERLAMINAR STESSES IN COMPOSITE LAMINATES

Department of Flight Vehicle Design and Applied Mechanics Beijing Institute of Aeronautics and Astronautics, Beijing, China

摘要

摘要: 本文针对pipes-Pagano模型建立了基于修正的Hahn-T sai非线性本构关系的准三维非线性有限元模型。分析了由一种具有明显材料非线性的碳/环氧复合材料构成的[45/-45]_s角交层板和正交对称层板的层间应力分布。结果表明:和弹性模型结果相比,当承受相同载荷时,材料非线性的存在在一定程度上会引起层间剪应力的降低,但对层间正应力的影响并不明显。

Abstract: In order to predict and suppress delamination in composite laminates,a comprehensive knowledge about the mechanism of interlaminar stresses in compasite laminates is necessary. In the present paper, a nonlinear quasi-three-dimensional finite element procedure is presented,in which a mpdified Elahn-Tsai nonliner constitutive equation is used.The results for an angle-ply [±45]_s and symmetric cross-ply laminates are presented. The lamina properties in the laminates have obvious nonlinearity in shear deformation and a little in transverse tension.Emphasis is placed on assessing the stress behavior in the regions close to ply-interface and exposed free edge.Compared with elastic results,the solutions indicate that material nonlinearities can cause the decrease in interla minar shear stresses to a certain degree,but they have little effect on the distributions of interlaminar normal stress.