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Fast Adaptive Global Digital Image Correlation

Yang, Jin and Bhattacharya, Kaushik (2018) Fast Adaptive Global Digital Image Correlation. In: Advancement of Optical Methods & Digital Image Correlation in Experimental Mechanics. Conference Proceedings of the Society for Experimental Mechanics Series. Vol.3. Springer , Cham, pp. 69-73. ISBN 978-3-319-97480-4. https://resolver.caltech.edu/CaltechAUTHORS:20201215-100834960

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Abstract

Digital image correlation (DIC) is a powerful experimental technique to compute full-field displacements and strains. The basic idea of the method is to compare images of an object decorated with a speckle pattern before and after deformation, and thereby to compute displacements and strains. Since DIC is a non-contact method that gives the whole field deformation, it is widely used to measure complex deformation patterns. Finite element (FE)-based Global DIC with regularization is one of the commonly used algorithms and it can be combined with finite element numerical simulations at the same time (Besnard et al., J Strain Anal Eng Design 47(4):214–228, 2012). However, Global DIC algorithm is usually computationally expensive and converges slowly. Further, it is difficult to directly apply an adaptive finite element mesh to Global DIC because the stiffness matrix and the external force vector have to be rebuilt every time the mesh is changed. In this paper, we report a new Global DIC algorithm that uses adaptive mesh. It builds on our recent work on the augmented Lagrangian digital image correlation (ALDIC) (Yang and Bhattacharya, Exp Mech, submitted). We consider the global compatibility condition as a constraint and formulate it using an augmented Lagrangian (AL) method. We solve the resulting problem using the alternating direction method of multipliers (ADMM) (Boyd et al., Mach Learn 3(1):1–122, 2010) where we separate the problem into two subproblems. The first subproblem is computed fast, locally and in parallel, and the second subproblem is computed globally without image grayscale value terms where nine point Gaussian quadrature works very well. Compared with current Global DIC algorithm, this new adaptive Global DIC algorithm decreases computation time significantly with no loss (and some gain) in accuracy.


Item Type:Book Section
Related URLs:
URLURL TypeDescription
https://doi.org/10.1007/978-3-319-97481-1_7DOIArticle
ORCID:
AuthorORCID
Bhattacharya, Kaushik0000-0003-2908-5469
Additional Information:© 2019 The Society for Experimental Mechanics, Inc. First Online: 12 October 2018. We gratefully acknowledge the support of the US Air Force Office of Scientific Research through the MURI grant ‘Managing the Mosaic of Microstructure’ (FA9550-12-1-0458).
Funders:
Funding AgencyGrant Number
Air Force Office of Scientific Research (AFOSR)FA9550-12-1-0458
Subject Keywords:Digital image correlation (DIC); Adaptive mesh; Augmented Lagrangian; Alternating Direction Method of Multipliers (ADMM); Heterogenous deformation
Series Name:Conference Proceedings of the Society for Experimental Mechanics Series
Record Number:CaltechAUTHORS:20201215-100834960
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201215-100834960
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107085
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:15 Dec 2020 18:44
Last Modified:15 Dec 2020 18:44

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