The Application of DIC Method in the Investigation of Polymer Tensile Behaviors
图像相关法在高分子材料拉伸性能研究中的应用

Large strain tensile properties of Polycarbonate/ acrylonitrile butadiene styrene(PC/ABS) polymer were experimentally investigated at different environmental temperatures in this paper.A displacement measurement system based on digital image correlation(DIC) method was developed,and the suitability of the system was discussed.Instead of assuming constant volume during deformation,three directional deformations were recorded simultaneously.The variation of strain and strain rate during tension were studied according to the displacement field.It is shown that the displacement measurement system is effective to measure the large deformation field for materials such as polymer PC/ABS.It is observed that thickness contracts more than that of the width during tension;much higher strain rates appear in the necking area,while low strain rates appear in other sections.In spite of larger load dropping in the load vs displacement curve,no obvious stress dropping was observed in the true stress-strain curve.So that it could be concluded that the load dropping during tensile necking is mainly due to the reduction of cross section.The post yield true stresses for polymer PC/ABS are lower under higher environmental temperatures.