Study on the laser ablation behavior of carbon fiber reinforced polymer laminates under the air environment

During laser irradiation, carbon fiber reinforced polymer ( CFRP ) will undergo complex damage behavior. How to characterize its ablation behaviors under the air environment is of great significance to the thermal protection design of aerospace structures. However, current models lack the capability to accurately simulate the multi-parameter ablation behavior and failure mechanisms under combined laser-airflow effects. Firstly, considering ablation mechanisms of matrix pyrolysis, carbon fiber oxidation and sublimation a thermo-mechanical coupling model was constructed to obtain the temperature-dependent thermophysical and mechanical properties. Secondly, a numerical simulation method based on the Arbitrary Lagrangian-Eulerian (ALE) adaptive mesh and the traditional ablation kinetics is developed. Lastly, compared with the experimental results, this work elucidates the relative contributions of different ablation mechanisms of CFRP laminates and systematically predicts their laser ablation progression under the graded power density conditions. Coupled thermal-mechanical analysis model reveals that the contribution of each ablative mechanisms is distinctive at the different laser power densities of the laser ablation pit.