基于三维数字图像相关的低周疲劳试验研究  

Experimental study on low cycle fatigue based on 3-D digital image correlation

作　　者：魏良宝 蒋明[1] WEI Liang-bao;JIANG Ming(School of Civil Engineering, SUST, Suzhou 215011, China)

机构地区：[1]苏州科技大学土木工程学院

出　　处：《实验力学》2018年第3期410-418,共9页Journal of Experimental Mechanics

基　　金：国家自然科学基金项目(11172193)

摘　　要：为研究三点弯曲试件在低周疲劳载荷作用下,裂纹萌生、扩展与循环周期间的关系以及裂纹区域位移与应变场的变化规律,由万能试验机及数字循环加载控制系统对三点弯曲试件施加循环周期载荷。两组CCD和试验机同步采集记录系列交变载荷作用下试件裂纹周边区域的数字散斑图像及载荷,应用三维数字图像相关（Digital image correlation,DIC）技术计算裂纹尖端区域的位移及应变场。通过对裂尖区域位移、主应变等的分析,获得裂纹扩展长度与扩展率等的变化规律。In order to study the relationship among crack initiation,crack propagation and cyclic cycle and the variation of crack region displacement and strain field of three-point bending specimen under the low cycle fatigue loading,cyclic load is applied to three point bending specimen by universal testing machine and digital cyclic loading control system.Two groups of CCD and test machine synchronously collect and record the digital speckle image and the load of crack surrounding region of the specimen subjected to alternating loading.3-d digital image correlation（DIC）technique was used to calculate the displacement and strain field at the crack tip region.By analyzing the displacement of crack tip region and the principal strain,the variation patterns of crack propagation length and propagation rate were obtained.

关 键 词：三维数字图像相关 三点弯曲 低周疲劳 裂纹扩展 裂纹尖端 

分 类 号：TH113.1[机械工程—机械设计及理论]