中文摘要：

采用数字图像相关（DIC）方法研究了混凝土材料的压缩破坏。在压缩实验前,将混凝土外表层切除,裸露的细观形貌可以作为DIC技术中的自然散斑场。采用高分辨CCD进行表面图像采集,通过DIC技术处理后可以获得压缩破坏过程中的应变场分布。两端无约束的混凝土压缩破坏符合第二强度理论（最大拉应变强度理论）,因此本文分析了混凝土压缩破坏前垂直荷载方向的拉应变场的分布规律。实验结果表明,在压缩破坏发生前,拉应变已经出现应变集中的现象,并且该应变集中与混凝土最后的压缩破坏形态有关。从细观形貌来看,混凝土破坏前的最大拉应变往往出现在骨料上,导致骨料内部开裂或者骨料边界开裂。本文研究结果表明,DIC技术可以提前预测出混凝土破坏的位置,适用于混凝土结构破坏的监测。

英文摘要：

Digital image correlation（DIC） method was used to research the compression damage of concrete.As natural speckles,the exposed meso-surfaces removing outer layer of concrete were captured by high resolution CCD.Since the damage of concrete coincides with second strength theory,the horizontal strain distributions on the surfaces of concrete structure before failure were analyzed by correlating these speckle images before and after deformation.The results show that the strain concentration always appear at aggregate before failure and cause it internal cracking or edge cracking.This study implies that DIC technique is useful for damage continuous inspections of concrete structure.