Effect of Process Parameters and Temperature on Delamination Propagation of Resistance‐Welded Thermoplastic Composites

In this article, the resistance‐welded glass fiber‐reinforced polypropylene thermoplastic composite double cantilever beam specimen was designed and prepared, and experiments on inter‐facial delamination propagation of resistance‐welded thermoplastic composite laminates were carried out with different process parameters (welding current, welding time, and electrode pressure) and temperatures. The effects of resistance welding process parameters and high temperature environment on the process of inter‐face delamination propagation of resistance welded thermoplastic composites were investigated. The results showed that the fracture toughness was reduced by 33.5% at 20 A compared to 19 A current condition. The fracture toughness decreased by 80.76% at 240 s compared to 300 s energization time. Fracture toughness was reduced by 45.67% at 0.15 MPa compared to 0.1 MPa electrode pressure. Due to the severe softening of the matrix at high temperatures, resulting in interlayer damage dominated by matrix fracture and a small amount of fiber bridging, the fracture toughness decreases with increase in temperature at 45°C, 65°C, and 85°C as compared to room temperature.