Property Evolution of CFRP Laminate Adhesive Joints under Hygrothermal Environments
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 ac-celerated 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 differ-ent 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 adhe-sive 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 ad-hesive has better baking resistance than that of DP6330 polyurethane adhesive.After moisture absorp-tion,the strength,stiffness and maximum fracture displacement of CFRP adhesive joints are de-creased.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.
万方数据
维普
