Abstract

This study is dedicated to implement hygro-thermo-mechanical nonlinear analysis of curved thin and moderately thick shallow panels, in which Functionally Graded Materials (FGMs) are employed through the thickness. Based on the rule of mixture, three different patterns of FGMs, including power, exponential and sigmoid patterns are used in formulation. The distribution of porosity within the material is also considered to be uniform. Therefore, the elastic modulus and Poisson’s ratio have a linear function. It is worth mentioning that thermal-dependency of materials is ignored, and it is assumed to be Thermal-Independent (TID). On the other hand, the shell structures are analyzed under the effects of hygro-thermal, mechanical and hygro-thermo-mechanical loads separately. It is aimed to obtain the post-buckling structural behavior, by considering large displacements and rotations. Some well-known benchmark problems are also considered to indicate the high accuracy, capability and performance of the proposed formulation in the nonlinear analysis of FG shells. Moreover, the influences of several parameters, such as, FGM patterns, thermal and moisture expansion coefficients and curvature ration of structure on the obtained results are accurately investigated.

摘要

本研究致力于对弯曲的薄板和中等厚度的浅板进行湿热力学非线性分析，其中在整个厚度范围内采用功能梯度材料 (FGM)。基于混合规则，在公式中使用了三种不同的 FGM 模式，包括幂、指数和 sigmoid 模式。材料内的孔隙率分布也被认为是均匀的。因此，弹性模量和泊松比具有线性函数。值得一提的是，材料的热依赖性被忽略了，它被假定为与热无关（TID）。另一方面，壳结构分别在湿热、机械和湿热机械载荷的作用下进行分析。其目的是获得屈曲后的结构行为，通过考虑大位移和旋转。一些著名的基准问题也被认为表明了所提出的公式在 FG 壳非线性分析中的高精度、能力和性能。此外，还准确研究了 FGM 模式、热膨胀系数和湿膨胀系数以及结构曲率比等几个参数对所得结果的影响。