Use of Taylor series-based image reconstruction method in Spectral digital image correlation(SDIC)

 

(Digital Image Correlation-DIC is a non contact technique to measure the surface displacement of a specimen by comparing digital images taken at different stages of deformation)

1. Taylor Series vs. Direct Fourier Transform: The paper introduces the Taylor series image reconstruction method, which increases efficiency over the conventional DFT-based method. Using third- and fourth-order Taylor series expansions leads to computational improvements by factors of 57 and 46, respectively.

2. Higher-order expansions improve the accuracy of deformation measurements and provide better noise resistance compared to the DFT method. This is particularly useful when Gaussian noise is introduced in the images.

3. Simulations were conducted using different strains and noise levels. The results showed that the Taylor series method performs comparably to or better than the DFT method in terms of accuracy, with significantly faster computation speeds.

4. Real-world Application: The proposed method was validated through experiments on a silicone rubber specimen under uniaxial tension. The displacement and strain measurements were consistent with theoretical expectations, highlighting the method's practical utility.

As per experiments, the standard deviations of displacement under different strains and noise levels, showing that the Taylor series method handles noise better than the Direct Fourier Transform method.

Conclusion:

The study demonstrates that replacing DFT with Taylor series expansions for image reconstruction in SDIC leads to substantial gains in computational speed while maintaining or improving the accuracy of strain and displacement 

measurements. This method is especially beneficial in handling large deformations and noisy conditions, making it highly applicable for real-time and high-precision measurements in various engineering and scientific fields