Accurate kinematic measurement at interfaces between dissimilar materials using conforming finite-element-based digital image correlation. (June 2016)

• Record Type: Journal Article
• Authors: Tao, Ran; Moussawi, Ali; Lubineau, Gilles; Pan, Bing
• Is Part Of: Optics and lasers in engineering. Volume 81(2016:)
• Page Start: 103
• Page End: 112
• Publication Date: 2016-06
• Subjects: Digital image correlation -- Dissimilar material interface -- Conformal mesh -- Global DIC; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2016.01.012
• Languages: English
• ISSNs: 0143-8166

Abstract

Abstract: Digital image correlation (DIC) is now an extensively applied full-field measurement technique with subpixel accuracy. A systematic drawback of this technique, however, is the smoothening of the kinematic field (e.g., displacement and strains) across interfaces between dissimilar materials, where the deformation gradient is known to be large. This can become an issue when a high level of accuracy is needed, for example, in the interfacial region of composites or joints. In this work, we described the application of global conforming finite-element-based DIC technique to obtain precise kinematic fields at interfaces between dissimilar materials. Speckle images from both numerical and actual experiments processed by the described global DIC technique better captured sharp strain gradient at the interface than local subset-based DIC. Abstract : Highlights: Global FE-DIC is used to capture displacement discontinuities at interfaces. We investigate effect of non-regular meshes on Global FE-DIC performance. The method performs well on two examples involving severe discontinuities.