Abstract
Carbon fiber reinforced thermoplastics (CFRTP), which is expected to reduce the weight of transportations and stainless steel (SUS304) were joined in the form of lap joint by a semiconductor laser (3kW, CW(continuous wave), 0.8-1.2m/min) using insert materials of thermoplastic elastomer sheet. When the irradiation speed is 1.0m/min, the shear strength was the highest showing cohesive failure at the joining area. While, 0.8m/min and 1.2 m/min specimens were lower values than 1.0m/min specimens showing the interfacial failure. The fatigue strength was very similar results to the tensile shear strength. These laser-joint specimens were lower shear/fatigue strength than adhesive-joint specimens. From the results of thermo-elastic stress analysis using the thermography, the stress concentration was observed at the joining area just before the fatigue failure. From the characterizing energy dissipation and degradation evaluation, the 1.0m/min laser-joint specimens showed higher value than the adhesive joint specimens during fatigue tests. It can be assumed that the laser-joint specimen accelerated the process of failure as compared with the adhesive-joint specimen.
