EFFECT OF TRIAXIAL STRESS CONSTRAINT ON THE FRACTURE AND TOUGHENING MECHANISMS OF PC/ABS BLENDS

摘要

Effect of triaxial stress constraint on the fracture and toughening mechanisms of polymers are investigated.rnPolycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) and PC/ABS blends are considered. A series ofrncircumferentially blunt-notched bars are used to generate different triaxial stress constraint. Thernfracture surfaces of specimens with different notch radius are examined by scanning electron microscopern(SEM). It is shown that the fracture strain and the fracture plastic strain energy density decrease forrnPC and PC/ABS blends, but increases for ABS, with the increase of stress triaxiality. It can be concludedrnthat tensile stress triaxiality makes PC brittle, but results in the toughening of ABS and PC/ABS blends,rnwhich is significantly different from the conventional metallic materials. It is also shown that ABS contentrnhas important effect on the deformation, fracture and toughening of PC/ABS blends