Effect of cyclic loading on tensile properties of PC and PC/ABS

The effects of cyclic loading on tensile fracture properties of polycarbonate (PC) and the alloy of polycarbonate and acrylonitrile-butadiene-styrene (PC/ABS) are experimentally investigated in the paper. Two digital cameras are used to record simultaneously the tensile deformation of specimens and the large deformation and the necking process of these polymers are discussed. Two lateral contractions are not identical at the later tensile stages and the contraction ratios in each lateral direction are related with the tensile strains in axial direction on width and thickness surface. The curvature radiuses at the minimum section during necking process are shown. The volume increases during necking process and then decreases gradually. The yield stress and fracture stress of PC/ABS are lower than that of PC. The degradation of the fracture stress and fracture strain due to the application of cyclic loading is larger for PC than that for PC/ABS, and these can be used to explain qualitatively why PC has higher fatigue crack growth rate than PC/ABS.