Extraction, modeling and impact analysis of porosity defects formed in the CFRTP /Al6061 laser direct joining process

Abstract This study focuses on the influence laws of porosity defects on the performance of the joint formed in the CFRTP/Al6061 laser direct joining process. Image extraction and finite‐element modeling methods are introduced to investigate the porosity defects, so that the model of joint with porosity defects of real characteristics is established. With the model, the failure process of the joints formed under different laser direct joining processes are analyzed, and the change law of the maximum failure displacement and the maximum failure load of the joints are revealed. The maximum error is within 17%. Results suggest that if and only if the porosity defects are distributed in the zone of the joint with the biggest stress under load, the defects will significantly decrease the maximum failure load of the joint; otherwise, the porosity defects will facilitate the cracking propagation process after the joint failure, thereby decreasing the maximum failure displacement. Highlights Porosity defects are identified from CFRTP background by image extraction. Local porosity is defined to illustrate the real distribution of defects. Joints with defects distributed by real characteristics are modeled. Max failure load hinges on relative position of defects and max stress zone. Porosity defect quantity influences cracking propagation rate after failure.