Research on a New Exponential Function Weighted Averaging Method Used for Full-Gradient Strain Measurement of DIC

The article introduces a new exponential function weighted averaging method (EFWA) for enhancing strain measurement accuracy in Digital Image Correlation (DIC). This method addresses the challenge of accurately measuring full-gradient strain fields, which are often corrupted by noise. The EFWA method uses a new exponential function to weight the displacement gradients and a self-adaptive selection strategy for the function parameters. This approach allows the method to preserve high-gradient strain results and effectively smooth low-gradient strain results. The method is validated through numerical experiments on synthetic images and experimental images from a tensile test, demonstrating its superior performance compared to existing methods. The article also concludes with a recommended subregion size for practical implementation.