图像相关法在高分子材料拉伸性能研究中的应用  

The Application of DIC Method in the Investigation of Polymer Tensile Behaviors

作　　者：方钦志[1] 李慧敏[1] 欧阳小东 赵泳 

机构地区：[1]西安交通大学工程力学系/强度与振动教育部重点实验室,西安710049 [2]南京聚隆工程塑料有限公司,南京210061

出　　处：《实验力学》2006年第4期459-466,共8页Journal of Experimental Mechanics

基　　金：国家自然科学基金项目(No.10472087);教育部重点项目资助

摘　　要：本文对聚碳酸酯(PC)和丙烯腈丁二烯苯乙烯(ABS)的合金(PC/ABS)高分子材料不同环境温度下的拉伸性能进行了试验研究。根据图像相关分析法编制了图像法位移测量分析软件,并对该分析软件的适用性进行了分析。系统研究了PC/ABS高分子材料拉伸试验时三个方向的位移场和应变场。根据测得的位移场研究了该高分子材料拉伸过程中应变和应变率的变化以及应力应变变化规律,并对试验结果进行了详细分析。结果表明,文中采用的图像法位移测量系统具有较高的测试精度;拉伸过程中,试件厚度方向的收缩变形大于宽度方向的收缩变形;颈缩过程区具有非常高的应变率,颈缩后的平直颈缩区的应变率快速下降到一个很低的应变率继续缓慢变形;尽管载荷位移曲线出现了较大的载荷下降现象,PC/ABS拉伸时的真应力应变曲线没有明显的应力下降现象出现,因此,载荷下降现象主要由颈缩时的截面减小引起;高分子材料PC/ABS的屈服应力随环境温度的升高而降低。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.

关 键 词：位移场 大应变 应变率 高分子 测试技术 

分 类 号：O348[理学—固体力学]