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 laser effects. Firstly, considering ablation mechanisms of matrix pyrolysis, carbon fiber oxidation and sublimation a thermo-mechanical coupling model is constructed to obtain the temperature-dependent thermophysical and mechanical properties. Secondly, a numerical calculation method based on the ' birth and death element method ', adaptive mesh technique ( ALE) and traditional ablation dynamics model is developed. Lastly, by comparing with experimental results, this work elucidates the relative contributions of different ablation mechanisms in CFRP laminates and systematically predicts their laser ablation progression under graded power density. The experimental results show that the Maximum ablation depth of CFRP laminates reaches 267.43µm and 783.88µm respectively when the laser power was 1,000 W and 2,000 W under the air environment, which verifies the accuracy of the improved technology and model. At the same time, it was found that under the air environment, when the laser power changes from 1,000 W to 2,000 W, the ablation mechanisms change from carbon fiber oxidation to carbon fiber oxidation and carbon fiber sublimation.