Bilinear approximations to the mixed-mode I–II delamination cohesive law using an inverse method. (April 2015)

• Record Type: Journal Article
• Authors: de Morais, A.B.; Pereira, A.B.; de Moura, M.F.S.F.; Silva, F.G.A.; Dourado, N.
• Is Part Of: Composite structures. Volume 122(2015)
• Page Start: 361
• Page End: 366
• Publication Date: 2015-04
• Subjects: Delamination -- Mixed-mode I–II -- Mixed-mode bending -- Cohesive law -- Inverse method; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2014.11.058
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: This paper presents an experimental and numerical study of the mixed-mode I–II delamination of unidirectional carbon/epoxy laminates. Double cantilever beam, end-notched flexure and mixed-mode bending tests were conducted in order to cover the full range of mode-mix combinations. Finite element cohesive zone models with a bilinear softening cohesive law were subsequently employed to fit experimental load–displacement curves. This required a genetic algorithm to find optimal bilinear softening parameters. Good agreement was achieved between predicted and experimental curves. Furthermore, the bilinear softening parameters showed consistent variations with the global mode-mix that could be interpreted in terms of local damage mechanisms. Nevertheless, further research is needed to define mixed-mode tractions and separations leading to a unique cohesive law.