受弯曲对称复合材料层板的层间应力分析

 本文引伸了受均匀拉伸复合材料层板自由边界效应问题的准三维有限元理论,分析了受弯曲（±45）_s角交层板与正交对称层板中的应力响应。着重讨论了层板自由边附近及层间界面上的应力分布。与受均匀应变拉伸下的应力分布相比,受弯曲对称复合材料层板中的层间应力分布有许多不同的特点。本文的分析结果将有助于理解在复合载荷下复合材料层板的破坏模式与破坏过程。

INTERLAMINAR STRESS ANALYSIS IN SYMMETRIC COMPOSITE LAMINATES UNDER BENDING

This paper extends the quasi-threedimensional finite element procedure to investigate the free edge effects in symmetric composite laminates of finite width under bending. An angle-ply （±+45） laminate and symmetric cross-ply laminates are analysed. Emphasis is placed on discussion of the singular behavior of stresses in the regions close to ply-interfaces and the exposed free edge.The solutions indicate that complex stress states with large gradients occur along the edge of composite laminates. This phenomenon is consistent with that in the laminates subjected to uniform axial strain. Owing to the antisymmetry of deformation and loading, the laminate is divided into two parts by middle plane. One half of the laminate is subjected to axial extension and the another to axial compression. Therefore, the stress response of composite laminates under bending becomes more complex. The stress distributions in the laminates under bending, compared with that under uniform axial extension, have many special features. The results presented in this paper will help us better understand the failure mode and failure process of composite laminates under complex loading.