Hydrothermal effects on mechanically fastened glass/polypropylene composite joints

Abstract This study deals with the hydrothermal effects on mechanically fastened glass fiber mat/polypropylene composite joints with different joint geometry. Three kinds of joint geometries were adopted; hole diameter was 6 mm, the length from top edge to the hole center was 18 mm (3e) and the specimen width was 12 (2 w), 18 (3w), and 30 mm (5w). The joints were immersed in hot water at 60 and 80°C. The effect of water temperature on the failure load appeared clearly in 2w3e joints. The higher water temperature induced more strength reduction. The dominant failure mode changed from the net‐tension to the bearing for the original dry joints for wider specimens. The failure mode changed from multiple to net‐tension only for 3w3e joints, because of a remarkable tensile strength reduction. The failure strength and the failure mode were predicted by the macroscopic failure criterion, and the characteristic experimental curves, and the FEM analysis. The predicted results agreed with experiment.