On the benefits of correcting brightness and contrast in global digital image correlation: Monitoring cracks during curing and drying of a refractory castable

Autor(es)

Sciuti, V. F. ^[1] ; Canto, R. B. ^{[2, 1]} ; Neggers, J. ^[3] ; Hild, F. ^[4]

Afiliação do(s) autor(es)

^[1] Fed Univ Sao Carlos UFSCar, Grad Program Mat Sci & Engn, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Fed Univ Sao Carlos UFSCar, Dept Mat Engn DEMa, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Paris Saclay, Cent Supelec, CNRS, Lab Mecan Sols Struct & Mat, Gif Sur Yvette - France

^[4] Univ Paris Saclay, ENS Paris Saclay, CNRS, LMT Lab Mecan & Technol, Gif Sur Yvette - France

• Tipo de documento: Artigo Científico
• Fonte: OPTICS AND LASERS IN ENGINEERING; v. 136, JAN 2021.
• Citações Web of Science: 1

Resumo

The gray level conservation is the underlying hypothesis of Digital Image Correlation (DIC). However, it may be challenging to enforce in some experimental configurations. Brightness and contrast corrections (BCCs) may be added to the registration procedure. Different types of BCCs were implemented for global DIC, and their benefits were analyzed for localized and diffuse sources of brightness changes. As a case study to apply BCCs, a refractory castable was placed inside a climatic chamber, and cracks were generated due to localized expansions during its curing and drying. To choose the best BCC for this case, two sets of images were considered. The first one allowed the noise floor levels to be evaluated. The second one dealt with the development of a crack network. The BCCs significantly reduced gray level residuals enabling cracks with small openings to be detected. The coarse discretization was effective in correcting lighting changes and avoided its coupling with the measured kinematic fields and other local phenomena. (AU)

• Processo FAPESP: 18/15266-0 - Detecção e quantificação de mecanismos de fratura de cerâmicas em temperatura ambiente e elevada via correlação de imagens digitais
• Beneficiário: Rodrigo Bresciani Canto
• Modalidade de apoio: Auxílio à Pesquisa - Regular