Static and fatigue failure of glass fibre reinforced polyster resins under complex stress conditions

Abstract

Static and fatigue tests have been carried out at several principal stress ratios on thin-walled tubes fabricated from “E” glass chopped strand mat and a polyester resin. Corresponding data have been obtained from flat laminates under axial tension, axial compression, and in-plane shear loading. The onset of debonding, and resin cracking were observed as well as rupture. The results have been compared with predictions based on the theories of failure for anisotropic materials. Only those theories which include the results of a complex stress test gave safe predictions. The fatigue results for cylinders gave failures at much lower stresses than would have been expected from corresponding axial stress data and further work is required to explain the anomaly.