中文摘要：

针对传统的数字图像相关法因相关性较低而难以测量高分子材料的超大变形问题,提出了一种修正的数字图像相关法进行全场全过程测量高分子材料应变。首先,提出一种基于多核点的初值匹配方法,提高了匹配点对的鲁棒性及高效性;然后,介绍一种多基准匹配方法,极大提高了数字图像相关法相关性;最后,根据以上关键技术研发的超大变形测量系统对单向拉伸的高密度聚乙烯试件进行测量。试验结果表明,本文方法能实时、动态、全场测量应变分布大于500%的高分子材料变形状态,为全场测量超大应变高分子材料应变提供了一种有效的非接触测量手段。

英文摘要：

The traditional digital image correlation method is difficult to measure polymer materials deformation directly because of its low correlation.The measurement of large deformation is a significant problem for engineering.In this paper,we propose a modified digital image correlation method to measure the large deformation in the whole process of polymer materials.Firstly,a kind of initial matching method based on multiple core points is proposed to improve the matching points on the robustness and efficiency;then,a modified digital image correlation method,which can improve the correlation based on multiple benchmark matching method,is introduced;Finally,according to the above key technology research,the large deformation measurement system is developed to measure large deformation of density polyethylene by the uniaxial tensile test.Experimental results show that the method can realize real time,dynamic,full field measurement of greater than 500% strain distribution of the polymer materials deformation states.The method provides an effective non-contact measurement way and has high practical value in engineering.The measurement of large deformation has the vital significance especially for new materials research in mechanical properties.