Bilinear approximations to the mixed-mode I-II delamination cohesive law using an inverse method

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 cohe...

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Bibliographic Details
Main Author: Morais, Alfredo (author)
Other Authors: Pereira, António Bastos (author), Moura, M. F. S. F. de (author), Silva, F. G. A. (author), Dourado, N. (author)
Format: article
Language:eng
Published: 1000
Subjects:
Online Access:http://hdl.handle.net/10773/21144
Country:Portugal
Oai:oai:ria.ua.pt:10773/21144
Description
Summary: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.