关键词: 碳纤维复合材料, 胶接接头, 烘烤, 湿热, 连接强度

Abstract:  In order to study the adaptability of CFRP adhesive joints to the high temperature and high humidity environments in the automobile painting processes, the experiments of baking and accelerated moisture absorption of single lap CFRP adhesive joints were carried out. The shear tensile and normal tensile tests of bonded joints undergoing different environmental tests were performed. The strength changes and failure mode evolution of CFRP adhesive joints were discussed under different environments. The adaptability of the joints bonded by epoxy resin and polyurethane adhesives to baking was compared, and the effects of adding spew fillet at the edge of the lap area on improving the joint strength were studied. The results show that the shear tensile strength of single lap CFRP adhesive joints is much higher than the normal tensile strength. After baking treatment, the strength of CFRP laminates and CFRP adhesive joints are increased instead of decreasing. DP420 epoxy resin adhesive has better baking resistance than that of DP6330 polyurethane adhesive. After moisture absorption, the strength, stiffness and maximum fracture displacement of CFRP adhesive joints are decreased. The failure modes of the joints are gradually evolved from the cohesive failure of the adhesive layers to the inter-laminar failure of the CFRP laminate. For single lap CFRP adhesive joints, adding a spew fillet at the edge of the lap area may effectively enhance the tensile shear strength.

Key words:  , carbon fiber reinforced plastic(CFRP), adhesive joint, baking, hygrothermal, joining strength