Some practical considerations in finite element-based digital image correlation
Type
ArticleKAUST Department
Composite and Heterogeneous Material Analysis and Simulation Laboratory (COHMAS)Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
Date
2015-04-20Online Publication Date
2015-04-20Print Publication Date
2015-10Permanent link to this record
http://hdl.handle.net/10754/564201
Metadata
Show full item recordAbstract
As an alternative to subset-based digital image correlation (DIC), finite element-based (FE-based) DIC method has gained increasing attention in the experimental mechanics community. However, the literature survey reveals that some important issues have not been well addressed in the published literatures. This work therefore aims to point out a few important considerations in the practical algorithm implementation of the FE-based DIC method, along with simple but effective solutions that can effectively tackle these issues. First, to better accommodate the possible intensity variations of the deformed images practically occurred in real experiments, a robust zero-mean normalized sum of squared difference criterion, instead of the commonly used sum of squared difference criterion, is introduced to quantify the similarity between reference and deformed elements in FE-based DIC. Second, to reduce the bias error induced by image noise and imperfect intensity interpolation, low-pass filtering of the speckle images with a 5×5 pixels Gaussian filter prior to correlation analysis, is presented. Third, to ensure the iterative calculation of FE-based DIC converges correctly and rapidly, an efficient subset-based DIC method, instead of simple integer-pixel displacement searching, is used to provide accurate initial guess of deformation for each calculation point. Also, the effects of various convergence criteria on the efficiency and accuracy of FE-based DIC are carefully examined, and a proper convergence criterion is recommended. The efficacy of these solutions is verified by numerical and real experiments. The results reveal that the improved FE-based DIC offers evident advantages over existing FE-based DIC method in terms of accuracy and efficiency. © 2015 Elsevier Ltd. All rights reserved.Citation
Wang, B., Pan, B., & Lubineau, G. (2015). Some practical considerations in finite element-based digital image correlation. Optics and Lasers in Engineering, 73, 22–32. doi:10.1016/j.optlaseng.2015.03.010Publisher
Elsevier BVJournal
Optics and Lasers in Engineeringae974a485f413a2113503eed53cd6c53
10.1016/j.optlaseng.2015.03.010