初始缺陷对正交叠层圆柱曲板临界载荷的影响

EFFECT OF INITIAL IMPERFECTIONS ON CRITICAL LOAD OF CYLINDRICALLY CURVED CROSS—PLY PANELS

本文应用动态松弛法(DRM)研究了承受均匀轴向压力的硼/环氧复合材料正交叠层(90°/0°)圆柱曲板在加载过程中的大挠度挠曲特性和初始几何缺陷对临界载荷的影响。文中考虑了两种弯曲边界条件;一种是四边简支;另一种是承载边为夹支而非承载边为简支。面內边界条件则假定板的周边在几何上不受约束。数值结果表明,初始几何缺陷使临界载荷显著下降,且下降的幅度与缺陷的严重程度及边界条件有关。

In this paper,Dynamic Relaxation Method is applied to inves- tigate the large deflection buckling behaviour of cylindrically curved cross—ply(90°/0°)panels made of Boron/Epoxy compo- site materials under uniform axial compression and the effect of initial geometric imperfections on the critical load of the panels in the case of loading.The two kinds of bending boundary condi- tions have been considered.In one case the all four edges are simply supported,in the other the two loaded edges are clamped and other two non—loaded edges are simply supported.In both of the above cases all the edges are assumed to be geometrically free in—plane.Numerical results show that the initial geometric imper- fections significantly reduce the critical load of the panels and the extent of this reduction is concerned with severity of the imperfec- tions and the boundary conditions.