Bisection Searching based Reference Frame Update Strategy for Digital Image Correlation
The strategy to update the reference frames in the digital image correlation analysis is an essential but often overlooked problem. A good reference frame update strategy should be able to adjust the frame step in respect of varying practical circumstances including the different loading rate, speckle pattern, plastic deformation, imaging system, lighting condition, etc. In this work, a simple but effective bisection searching (BS) strategy is presented to solve this problem. The frame step is reduced into one half for the unconverged locations, and the intermediate frame is utilized to assist the correlating process. This process is iteratively conducted to adjust the frame step in different regions automatically. The performance of the BS strategy is evaluated against the constant step (CS) update strategy on simulated experiments. The results indicate that the BS strategy can automatically adjust the frame step for changing speckle pattern and loading rate. The accuracy and robustness of the BS strategy are better than the CS strategy with the same pixel level and subpixel level searching algorithms. The BS strategy also successfully tracked all POIs and adjusted the frame step in the real world experiment with changing loading rate and large plastic deformation (over 70% engineering strain).
Y. Zhang et al., "Bisection Searching based Reference Frame Update Strategy for Digital Image Correlation," SN Applied Sciences, vol. 1, no. 588, Springer, Jun 2019.
The definitive version is available at https://doi.org/10.1007/s42452-019-0625-y
Mechanical and Aerospace Engineering
Intelligent Systems Center
Keywords and Phrases
Digital image correlation; Template update; Reference frame update; Bisection method
International Standard Serial Number (ISSN)
Article - Journal
© 2019 Springer, All rights reserved.
01 Jun 2019