Abstract: A experimental investigation of the resistance welding of carbon fibre reinforced epoxy laminate is presented. The bonding surface of the laminate is coated with a layer of binder as welding medium and the interpenetration polymer network was created between epoxy and binder during curing process. The temperature distribution of the welding interface was measured and compared to those simulated by finite element model, the statistical distribution of the resistance of the unidirection and fabric heating elements was characterized, and the effects of the temperature on the heating element resistance were evaluated. Maximum lap shear strengths of 7.35MPa was obtained using unidirectional heating element for the AX8900 bindered epoxy/CF laminate. Three failure mechanisms, leading to different values of lap shear strength, were identified including tearing of heating element, cohesive failure of the binders and interfacial failure. A comparison between unidirectional, fabric and mental mesh heating element, in terms of lap shear strength was performed. The results show that fabric and mental mesh heating element can significantly improve the lap shear strength. A processing window based on the parameters, i.e. power level and welding time, was crated.

Key words: thermosetting composites, resistance welding, thermoplastic binder, welding strength