Digital image correlation based on the pre-deformation assist strategy and an optimized checkerboard-like speckle pattern for large deformation measurement

Large deformation measurement is one of the main issues faced by the digital image correlation method, and the specially designed speckle pattern offers a promising solution. This Letter suggests an extremely simple method to fabricate an optimized speckle pattern for large deformation problems. It demonstrates a more effective large deformation initial estimation capability and measurement accuracy when combined with the pre-deformation assist strategy. A series of simulated and real experiments are used to test the effectiveness of the proposed method, and the results reveal that it performs significantly better than the traditional method in large deformation problems.