基于电子散斑干涉技术的混凝土裂纹扩展特性研究  

Behaviors of crack propagation in concrete using electronic speckle pattern interferometry

作　　者：王青原[1] 陈红鸟[1] 袁波[1] 黄兴震 赵艳兵[1] WANG Qingyuan;CHEN Hongniao;YUAN Bo;HUANG Xingzheng;ZHAO Yanbing(Space Structures Research Center, Guizhou University, Guiyang 55000)

机构地区：[1]贵州大学空间结构研究中心,贵阳550003

出　　处：《水力发电学报》2018年第4期26-35,共10页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(51408144);贵州省科学技术基金项目([2016]1040);贵州省留学人员科技创新项目([2016]17)

摘　　要：由于存在断裂过程区,混凝土材料的断裂行为表现出一定的非线性,材料的断裂性能对水工结构的承载力和耐久性评估至关重要。为了研究混凝土的非线性断裂行为,对带预制切口的混凝土梁进行三点弯曲试验,采用电子散斑干涉(ESPI)技术获得梁表面的位移场。通过分析梁试件在15个加载步下的裂纹扩展状态,即COD(裂纹张开位移)与a(裂缝长度)的关系,分析混凝土裂纹扩展规律。鉴于线弹性断裂力学(LEFM)公式不适用于裂纹尖端附近的位移计算,在ESPI测量结果的基础上,通过对COD-a曲线进行分段分析,建立了适用于裂缝全长度的COD-a的函数关系式。Fracture behaviors of concrete materials exhibit certain nonlinearity due to the existence of a fracture process zone（FPZ） and they play a crucial role in determining the bearing capacity and durability of hydraulic structures. To study the nonlinear fracture behaviors, we conduct three-point bending tests on pre-notched concrete beams and measure their full-field displacements using an electronic speckle pattern interferometry（ESPI）. Variations in crack evolution are examined through analysis on the relationships of crack opening displacement（COD） versus crack length a at 15 loading levels. And new formulas are derived for the COD-a relationships based on ESPI measurements to replace the existing formula that is based on linear elastic fracture mechanics（LFEM） and inapplicable near a crack tip.

关 键 词：断裂过程区 裂纹张开位移 裂纹扩展深度 三点弯曲 电子散斑干涉技术 

分 类 号：TU528.36[建筑科学—建筑技术科学]