A Coupled Thermo-mechanical Modelling Strategy Based on Alternating Direction Implicit Formulation for the Simulation of Multilayered CFRTP Thermo-stamping Process

A new thermo-mechanical strategy for modelling the thermo-stamping process of multilayered Carbon Fiber Reinforced Thermo-Plastics (CFRTP) materials is presented. It was derived from the use of a new two-dimensional thermo-mechanical finite element comprising a mechanical shell element covered by a thermal element based on the Alternating Direction Implicit (ADI) formulation. As a result, it was possible to solve a two-dimensional thermo-mechanical problem while obtaining the temperature distribution in the thickness direction of each layer. Applied to a viscohyperelastic constitutive law, a new invariant was proposed to model in-plane transverse elongations in unidirectional (UD) composite parts. The numerical simulation of the thermo-stamping process of a bi-layer UD PA66/Carbon Fiber prepreg revealed the potential of the presented approach. The new invariant was able to capture the anisotropic mechanical response of UD prepregs according to theorientation of the fibers. Furthermore, the ADI formulation made it possible to identify the distribution of the heat due to the contact between the prepregs and the tools through a thickness of several layers.