Computational and Experimental Study on the Resistance Welding Process of a Glass Fibre-Reinforced Epoxy-Based Composite with Thermoplastic Interlayer Adherent

Abstract

In this work, resistance welding of a glass fibre-reinforced epoxy composite (GFRC) was studied with numerical optimisation and experimental validation. A steel mesh and polymethyl methacrylate (PMMA) films were used as the heating element and adherent interlayers, respectively. A transient heat transfer module was implemented to conduct the parametric optimisation study, with variables of electricity power, clamping distance and weld time. The optimal welding condition was then confirmed as 20 W, 0.4 mm and 30 s, with the melting degree of 95.2 %. A thermal meter and a thermal camera validated the simulated temperature results. Welding quality was experimentally characterized by single lap shear tests and scanning electron microscopy (SEM). The highest lap shear strength of 3.8 ± 0.3 MPa was captured on the specimen welded with the optimised condition. This was 76 % that of the benchmark made with adhesive bonding method but it was over 200 times faster.