Incremental displacement measurement based on digital image correlation

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.