Accurate 3D modeling of laser-matter interaction in the AFP process by a conductive-radiative FEM approach

Abstract

Mainly driven by aeronautical demands, the Automated Fiber Placement (AFP) process has become pivotal in the in-situ manufacturing of intricate, high-performance composite components. AFP relies on robotic systems to meticulously lay continuous fiber-reinforced materials, employing controlled pressure and precise laser heating. Accurate thermal modeling is imperative to predict thermal effects impacting contact, adhesion, crystallinity, and residual constraints. This work introduces a novel numerical approach for efficient modeling the transient heat transfers in the AFP process using a coupled conductive-radiative finite element method (FEM) scheme. Radiative density from the laser-matter interaction is determined through an inhouse parallelized FreeFEM++ code. Heat transfer at the micro-scale is assessed by using an artificial computational geometry based on fiber distributions obtained from tape micrograph. A parametric study with varying absorption coefficients of the carbon fibers is performed to accurately compute the radiative volumetric heat source. The proposed approach investigates various 2D and 3D scenarios involving different laser parameters. Results exhibit strong agreement with experimentally obtained data, showing a maximum temperature difference of 5-6°C at the end of the heating phase. Furthermore, a 3D case demonstrates the potential of this approach for modeling complex micro-scale geometries.