Mechanical properties of composite T-joints subjected to laser ablation

Abstract

The tensile properties of composite T-joints after being subjected to laser ablation were investigated in this work. The ablation test results show that the area of ablation pits and heat affected zones decrease, while the ablation depth and mass loss rate increase as the spot diameter declines. There are massive coarse and fine cracks around the ablation zone, which have a significant impact on the tensile strength and failure mode of T-joints. The tensile test results indicate that the failure load decreases dramatically after laser ablation with decreasing spot diameter. The failure mode of the T-joints after laser ablation under tensile loading shows delamination at the interface of the triangular zone/skin. Finally, the progressive damage model (PDM) was established based on the cohesive zone model to reveal the tensile failure mechanism of T-joints with and without laser ablation. It was shown that laser damage primarily affects the interlaminar tensile and shear strength of the heat affected zone, leading to interlaminar failure in this region and thereby causing a decrease in the stiffness of the skin. The predicted results obtained by the PDM correspond well with those of the experiments.