拟椭圆槽孔层合板的孔边应力分布

STRESS DISTRIBUTION AROUND QUASI-ELLIPTIC NOTCH IN LAMINATED COMPOSITES

基于一种修正的余能原理,建立两类特殊杂交应力层合元,一种具有一个无外力圆柱表面元及一种具有一个无外力直表面元。单元分层假设应力场准确满足平衡方程、层间应力连续条件及下表面无外力边界条件。单元位移场允许每层横截面独立地转动,但保持层间界面上位移的连续性。应用这两类单元高效而精确地分析具有拟椭圆槽孔[+45/-45]s层合板的孔口附近应力分布。计算表明,在较粗的网格下它可以给出较一般位移元及一般杂交元更为精确的孔边应力解。

Two kinds of 3-dimensional assumed stress hybrid multilayer elements based on a modified complementary energy principle have been developed for efficient and accurate stress analysis around quasi-elliptic notch in laminated composites.One kind of element contains a traction-free cylindrical surface,the other contains a traction-free planar surface.The stresses of both elements are satisfied exactly the homogeneous equilibrium equation and the interlayer traction continuity condition.The displacements of each layer are assumed independent rotations of the normals to the plate mid surface for both elements.Transverse-shear deformation effects are incorporated in each layer with displacement continuity enforced along interlayer surface.The 3-dimensional stress distribution of [＋45/45]s orthotropic laminated plates with quasi-elliptic notch is efficiently analyzed by the use of combination of these two kinds of special hybrid stress elements.The example shows that this method is more efficient and accurate than by conventional displacement elements in coarse mesh.