Title

Bisection Searching based Reference Frame Update Strategy for Digital Image Correlation

Abstract

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).

Department(s)

Mechanical and Aerospace Engineering

Research Center/Lab(s)

Intelligent Systems Center

Comments

This study was funded by NASA EPSCoR (NNX13AM99A), National Science Foundation (CMMI-1625736), DOE STTR (DESC0018879), and the Intelligent Systems Center (ISC) and Material Research Center at Missouri S&T.

Keywords and Phrases

Digital image correlation; Template update; Reference frame update; Bisection method

International Standard Serial Number (ISSN)

2523-3963; 2523-3971

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2019 Springer, All rights reserved.

Publication Date

01 Jun 2019

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