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本文采用激光显微像面全息和散斑照像分离技术检测了双缺口试件在不同压缩应力条件下缺口根部塑性区的形状及大小,并采用有限元分析法计算了相同应力下的塑性区和裂端应力场.结果表明:用显微像面全息法测量塑性区的大小及形状简单易行,且有比较满意的工程精度. 对在不同压缩循环加载条件下测得的瘦劳裂纹止裂长度与所测压缩塑性区相比较表明:疲劳裂纹止裂长度和塑性区大小之间不存在简单的对应关系.止裂长度主要由缺口根部在循环压缩卸载过程中所产生的拉伸应力区控制.
In this paper, the shape and size of the plastic zone at the notch root under double-notched specimens under different compressive stress were examined by using laser micro-image plane holography and speckle photographic separation techniques. The plastic zone under the same stress was calculated by finite element analysis And cracked stress field.The results show that the size and shape of the plastic zone are simple and easy to measure with the microscope image holography method, and have satisfactory engineering accuracy.At the same time, The comparison between the crack length and the measured compressive plastic zone shows that there is no simple correspondence between the crack arrest length and the size of the plastic zone.The length of the crack arrest mainly depends on the tensile stress zone control.