Structural Integrity of Glass/Polyester Composites at Liquid Nitrogen Temperature

Abstract

The aim of present study is to investigate the interlaminar fracture behaviour of glass reinforced polyester composites at liquid nitrogen temperature. Short beam Shear (SBS) test, which generally promotes failure by interlaminar shear, was performed to assess interfacial bond strength between fibre and matrix. The mechanical assessment is extended to evaluate and compare the loading rate sensitivity of cryogenically conditioned and untreated glass/polyester composites at 2mm/min, 50mm/min, 100mm/min, 200mm/min and 500mm/min crosshead speeds. Microstructural changes after cryogenic treatment of glass/polyester composites were explained by Scanning Electron Microscope (SEM). The behaviour of these composites at cryogenic temperature may be attributed to stress relaxation, polyester curing shrinkage, large amount of residual stresses, cryogenic contraction of the matrix, greater misfit strains and matrix crackings.