Electromagnetic induction welding process and welding strength of aeronautical composite materials

A numerical model of electromagnetic induction welding is established based on the electro-magnetic-thermal multi-field co-simulation method to simulate the welding process. The welding strength of CFRP layer is analyzed by the Cohesive element and the secondary nominal strain failure criterion. The effects of the lap length of CFRP laminates and the thickness of PEEK adhesive layer on the welding strength were studied, and the simulation results were verified by single lap test. The results show that the temperature of the welded laminate is up to 385.7 ℃, the test result is 372.5 ℃ under the condition that the lap length is 12.5 mm and the thickness is 0.5 mm. The error between simulation results and test results is 3.5%. During the stretching process, the end of the welded joint is first damaged, and the tensile failure of the joint is caused by fiber pull-out failure, peeling failure and matrix cohesion failure. There is no obvious correlation between the welding strength of CFRP laminates and the lap length of laminates. The fracture type of PEEK adhesive layer is a mixed failure of open type and slip type. When the thickness of PEEK adhesive layer is 1mm, the calculated shear strength is 5.97 MPa.