Abstract

In spite of considerable importance in engineering practice, especially in aerospace structures, thermal postbuckling behavior of nanocomposite curved panels has received little attention. This article aims to analyze different situations of postbuckling response of carbon nanotube (CNT) reinforced composite flat and cylindrical panels exposed to uniform temperature rise. CNTs are embedded into isotropic matrix through functionally graded distributions. The properties of constitutive materials are assumed to be temperature dependent and effective properties of CNT-reinforced composite are estimated according to an extended rule of mixture. Governing equations of thick panels are established within the framework of higher order shear deformation theory taking into account geometrical nonlinearity, initial imperfection, panel-foundation interaction, and elasticity of tangential constraints of boundary edges. Analytical solutions for simply supported panels are assumed and Galerkin method is adopted to derive nonlinear load-deflection relations from which temperature-deflection equilibrium paths are traced through an iteration algorithm. The study reveals that combined effects of curvature of panel, tangential constraints of edges, and initial geometrical imperfection can lead to the change in type of buckling response. Numerical analyses also indicate different influences on the postbuckling behavior of thermally loaded nanocomposite panels.

摘要

尽管在工程实践中，特别是在航空航天结构中具有相当重要的意义，但纳米复合曲面面板的热后屈曲行为却很少受到关注。本文旨在分析碳纳米管（CNT）增强复合平板和圆柱板在均匀温升下的不同后屈曲响应情况。碳纳米管通过功能梯度分布嵌入到各向同性基质中。假定本构材料的性能与温度有关，并且根据混合的扩展规则估计 CNT 增强复合材料的有效性能。在考虑几何非线性、初始缺陷、面板-基础相互作用的高阶剪切变形理论框架内建立了厚面板的控制方程，和边界边缘的切向约束的弹性。假设简支板的解析解，并采用Galerkin方法推导出非线性载荷-挠度关系，通过迭代算法跟踪温度-挠度平衡路径。研究表明，面板曲率、边缘的切向约束和初始几何缺陷的综合影响会导致屈曲响应类型的变化。数值分析还表明对热加载纳米复合材料面板的后屈曲行为有不同的影响。假设简支板的解析解，并采用Galerkin方法推导出非线性载荷-挠度关系，通过迭代算法跟踪温度-挠度平衡路径。研究表明，面板曲率、边缘的切向约束和初始几何缺陷的综合影响会导致屈曲响应类型的变化。数值分析还表明对热加载纳米复合材料面板的后屈曲行为有不同的影响。假设简支板的解析解，并采用Galerkin方法推导出非线性载荷-挠度关系，通过迭代算法跟踪温度-挠度平衡路径。研究表明，面板曲率、边缘的切向约束和初始几何缺陷的综合影响会导致屈曲响应类型的变化。数值分析还表明对热加载纳米复合材料面板的后屈曲行为有不同的影响。