Characterization of resistance-welded thermoplastic composite double-lap joints.

摘要

An investigation of resistance welding of thermoplastic composite double-lap shear joints is presented. Double-lap shear specimens consisting of carbon fibre/poly-etherether-ketone (PEEK/CF), carbon fibre/poly-etherketone-ketone (PEKK/CF), carbon fibre/poly-ether-imide (PEI/CF) and glassfibre/poly-ether-imide (PEI/GF) were resistance-welded using a stainless steel mesh heating element. The objective of this work was to study the mechanical performances of the double lap shear resistance-welded joints and to compare them with the single lap shear resistance-welded joints. The welded specimens were analyzed using static and dynamic lap shear tests and optical and scanning electron microscopy. Lap shear strengths of 53 MPa, 49 MPa, 45 MPa and an extrapolated value of 34 MPa were obtained for PEEK/CF, PEKK/CF, PEI/CF and PEI/GF double-lap joints, respectively. Infinite fatigue lives were obtained at 30% for PEEK/CF and PEKK/CF, 25% for PEI/CF and 20% for PEI/GF. Resistance-welded double-lap joints were found to have equivalent static and fatigue mechanical properties compared with single-lap joints, for all materials tested.