【摘要】 将数字图像相关方法用于测量含I型双边裂纹复合材料薄板应力强度因子。首先,介绍了数字图像相关方法基本原理,通过最小二乘拟合法建立了裂纹尖端位移场与裂尖应力强度因子的关系。其次,搭建了数字图像相关方法非接触光学测试平台,通过对含I型双边裂纹复合材料薄板进行拉伸试验,得到了复合材料薄板双边裂纹尖端全场位移。最后,通过数字图像相关方法计算所得全场位移,提取了裂纹尖端应力强度因子,分析了最小二乘拟合项数、数字图像相关计算中子区域和步长大小的选择对裂纹尖端应力强度因子计算的影响。更多还原

【Abstract】 Digital image correlation method was used to measure mode-I stress intensity factor in a doublecracked composite sheet. First,the principle of DIC was introduced,and the relationship between the stress intensity factor and the displacement at the crack tip was established based on least square fitting. Then,the non-contact optical measurement system of DIC was built up,and the full field displacements at the crack tip were obtained by tensile experiments using double-cracked composite sheets. Finally,the stress intensity factors were extracted from the full field displacements,and the effects of least square fitting terms,sub size and sub spacing of DIC on the stress intensity factors were analyzed.更多还原