A Short Image Series Based Scheme for Time Series Digital Image Correlation

TL;DR

This paper introduces a novel short time series digital image correlation (STS-DIC) method that enhances deformation measurement accuracy by averaging multiple images and modeling deformation as linear over short time intervals.

Contribution

The paper proposes a new STS-DIC scheme that combines multiple images for improved accuracy and introduces a spatial-temporal displacement model with eight unknowns.

Findings

Significantly improves DIC accuracy under various deformation conditions

Maintains acceptable computational cost

Validated through numerical and experimental tests

Abstract

A new scheme for digital image correlation, i.e., short time series DIC (STS-DIC) is proposed. Instead of processing the original deformed speckle images individually, STS-DIC combines several adjacent deformed speckle images from a short time series and then processes the averaged image, for which deformation continuity over time is introduced. The deformation of several adjacent images is assumed to be linear in time and a new spatial-temporal displacement representation method with eight unknowns is presented based on the subset-based representation method. Then, the model of STS-DIC is created and a solving scheme is developed based on the Newton-Raphson iteration. The proposed method is verified for numerical and experimental cases. The results show that the proposed STS-DIC greatly improves the accuracy of traditional DIC, both under simple and complicated deformation conditions, while retaining acceptable actual computational cost.