Damage technology of carbon fiber composites by high-power laser

Abstract

Based on the layer characteristics of the carbon fiber and resin composites, the damage mechanism of high power laser beam on the carbon fiber target are investigated. Analyzing the laser ablation target, the layer ablation mechanism is introduced, which is composed of an ablation layer, a pyrolysis layer and an original layer. The finite element model of the laser ablation the carbon fiber composites was established, in which a Gaussian laser beam irradiated perpendicularly on the target. Because of the advantages of finite element gridding in spatial domain and finite difference gridding in time domain, the “birth and death element” method was used to accurately simulate the temperature distribution field of the laser damage target, and those elements were sequentially stripped, i.e. “killed”, exceeding the vaporization temperature “point” of the carbon fiber composites during the laser heating until the laser is shut off. Moreover, the laser damage experiment on the carbon fiber composites was carried out, the temperature distribution field of the laser irradiated target was measured, and the burn-through time of the carbon fiber target was recorded. It is found show that the birth and death element method with the sequent stripping way can be used accurately to simulate the three-dimensional temperature distribution field of the target and evaluate the laser damage efficiency to the targets.