A multiscale approach for the mechanical response of thermoplastic composite pipes

A multiscale semi-analytical framework is developed to analyze the mechanical response of thermoplastic composite pipes (TCPs) subjected to thermo-mechanical loads. The approach integrates an extended homogenization method with three-dimensional (3D) anisotropic elasticity theory, and incorporates temperature-dependent material properties to improve the accuracy of the analysis. Under the assumption of small strains and linear elastic material behavior, the superposition principle is applied to decouple the thermo-mechanical problem into mechanical and thermal subproblems. Within the extended homogenization framework, the homogenized elastic constants are derived based on force-deformation equivalence, enabling efficient stress analysis of multilayered composite cylinders with arbitrary fiber orientations by replacing detailed layer-by-layer models with simplified equivalent single-layer representations. The thermal stress analysis is performed by applying appropriate boundary and continuity conditions within the 3D anisotropic elasticity formulation. The proposed framework extends the traditional homogenization approach to accommodate arbitrarily oriented composite layers and temperature-dependent material properties while maintaining high computational efficiency. A parametric study is conducted to investigate the effects of different ply angles under various loading conditions, and the accuracy of the proposed model is verified through comparisons with established analytical solutions from the literature. • A multiscale semi-analytical model is proposed to predict the layer-wise stress response of Thermoplastic Composite Pipes under combined thermo-mechanical loads. • The extended homogenization method we proposed provides an efficient and fast approach for assessing composite risers with different materials, fiber angles, and layups. • More complex working conditions are taken into consideration. • Results verify the effectiveness and accuracy of the proposed method.