湿热环境中复合材料层合圆柱薄壳的屈曲和后屈曲

Buckling and Postbuckling of Laminated Thin Cylindrical Shells under Hygrothermal Environments

在宏_细观力学模型框架下 ,讨论湿热环境对复合材料层合圆柱薄壳在轴向压缩作用下屈曲和后屈曲行为的影响· 基于细观力学模型复合材料性能与湿度和温度变化有关· 壳体控制方程基于经典层合壳理论 ,并包括湿热效应· 壳体屈曲的边界层理论被推广用于湿热环境的情况 ,相应的奇异摄动法用于确定层合圆柱薄壳的屈曲荷载和后屈曲平衡路径· 分析中同时计及壳体非线性前屈曲变形和初始几何缺陷的影响· 数值算例给出完善和非完善正交铺设层合圆柱薄壳在不同湿热环境中的后屈曲行为· 讨论了温度和湿度 ,纤维体积比率 ,壳体几何参数 ,铺层数 。

The influence of hygrothermal effects on the buckling and postbuckling of composite laminated cylindrical shells subjected to axial compression is investigated using a micro_to_macro_mechanical analytical model. The material properties of the composite are affected by the variation of temperature and moisture, and are based on a micromechanical model of a laminate. The governing equations are based on the classical laminated shell theory, and including hygrothermal effects. The nonlinear prebuckling deformations and initial geometric imperfections of the shell were both taken into account. A boundary layer theory of shell buckling was extended to the case of laminated cylindrical shells under hygrothermal environments, and a singular perturbation technique was employed to determine buckling loads and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling behavior of perfect and imperfect, cross_ply laminated cylindrical shells under different sets of environmental conditions. The influences played by temperature rise, the degree of moisture concentration, fiber volume fraction, shell geometric parameter, total number of plies, stacking sequences and initial geometric imperfections are studied.