Resistance welding of thermosetting composite/thermoplastic composite joints

An investigation of the resistance welding between carbon fibre (CF)-reinfo rced polyetherimide (PEI) and CF-reinforced epoxy laminates is presented. A three-dimensional transient finite element model (FEM) featuring heat tran sfer, consolidation and thermal degradation was used for simulating the pro cess. A hybrid interlayer made of a glass fibre (GF) fabric essentially imp regnated with PEI on one side and with epoxy resin on the other side was pr oduced to provide mechanical interlocking between the thermoplastic JP) and the thermosetting (TS) systems. The 'optimal' resistance welding time base d on the maximum lap shear strength (LSS) was determined for three power le vels and correlated to the time required to achieve bonding predicted by th e FEM. Consolidation quality and failure mechanisms were discussed in relat ion with processing parameters. Experimental and simulated processing windo ws were constructed and correlated to each other. However, thermal degradat ion as predicted by the model did not correlate to a reduction in performan ce of the joint. (C) 2001 Elsevier Science Ltd. All rights reserved.