The present work develops a bio-inspired polyhedral composite lining to rehabilitate the cracked subsea pipeline. This functionally graded porous (FGP) polyhedral lining is subjected simultaneously to the thermal field and the mechanical loading field. The graphene platelets (GPL) are added to the FGP polyhedral lining to raise the bending stiffness of the pipeline-lining system. Both the Halpin-Tsai micromechanics model and Gaussian random field theory are adopted to express Young's modulus of the GPL and the distribution of the porosity, respectively. An assumed-shape function is developed to describe the deformation of the FGP-GPL polyhedral lining under combined loading fields. The equilibrium paths are traced explicitly by applying the energy function and nonlinear thin-walled shell theory. Analytical solutions are in good accordance with the other closed-form solutions from elsewhere. Afterward, an improvement factor is developed to examine the effect of polyhedral shapes on the bending stiffness. Finally, parametric evaluations are carried out to explore the effects of different parameters on the buckling responses of the polyhedral composite lining. These parameters include the porosity coefficient, weight fraction, geometric parameters of the GPL, polyhedral shapes, radius-to-thickness ratios, temperature variations, and so on.

中文翻译：

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联合加载场下裂纹海底管道多面复合衬里的屈曲响应


目前的工作是开发一种仿生多面体复合衬里来修复破裂的海底管道。这种功能梯度多孔（FGP）多面体衬里同时承受热场和机械载荷场。将石墨烯片（GPL）添加到FGP多面体衬里中，以提高管道衬里系统的弯曲刚度。采用Halpin-Tsai微观力学模型和高斯随机场理论分别表达GPL的杨氏模量和孔隙率分布。开发了假设形状函数来描述组合载荷场下 FGP-GPL 多面衬砌的变形。通过应用能量函数和非线性薄壁壳理论明确地追踪平衡路径。分析解决方案与其他地方的其他封闭式解决方案非常一致。随后，开发了一个改进因子来检查多面体形状对弯曲刚度的影响。最后，进行参数评估，探讨不同参数对多面复合衬砌屈曲响应的影响。这些参数包括孔隙率系数、重量分数、GPL 的几何参数、多面体形状、半径厚度比、温度变化等。