数字图像相关分析法增量位移场测试技术

Incremental Displacement Measurement Based on Digital Image Correlation

利用位移场的连续性,对亚像素位移场的算法进行了一些改进,设计了一套分步计算位移场、应变场的测量计算方法,较好地解决了数字图像相关分析法计算精度和效率。采用增量位移场叠加的方法计算大应变位移场,采用局部平面拟合的方法计算应变场。通过对高分子材料拉伸试验位移场的测量和结果标定,说明该方法具有较强的实用性和计算精度。同时,由于避免了对亚像素点的搜索,大大提高了计算效率。

The computational method for sub-pixel displacement field measurement with digital image correlation analysis is developed according to the continuous solid deformations. A program is designed to evaluate the integer, non-integer displacement fields and then the strain field without sub-pixed correlation cal-cutation. The large strain, displacement fields are obtained with the summation of the incremental displacement fields, the strain fields are described by the best fitting of local displacement fields with higher validity and accuracy.