Paper Title:

Mechanics of Composite Delamination under Flexural Loading

Periodical Key Engineering Materials (Volumes 462 - 463)
Main Theme Fracture and Strength of Solids VII
Edited by Ahmad Kamal Ariffin, Shahrum Abdullah, Aidy Ali, Andanastuti Muchtar, Mariyam Jameelah Ghazali and Zainuddin Sajuri
Pages 726-731
DOI 10.4028/www.scientific.net/KEM.462-463.726
Citation S.S.R. Koloor et al., 2011, Key Engineering Materials, 462-463, 726
Online since January 2011
Authors S.S.R. Koloor, A. Abdul-Latif, Mohd Nasir Tamin
Keywords CFRP Composite, Cohesive Zone Model (CZM), Flexural Load, Interface Damage, Interface Delamination
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The mechanics of interface delamination in CFRP composite laminates is examined using finite element method. For this purpose a 12-ply CFRP composite, with a total thickness of 2.4 mm and anti-symmetric ply sequence of [45/-45/45/0/-45/0/0/45/0/-45/45/-45] is simulated under three-point bend test setup. Each unidirectional composite lamina is treated as an equivalent elastic and orthotropic panel. Interface behavior is defined using damage, linear elastic constitutive model and employed to describe the initiation and progression of delamination during flexural loading. Complementary three-point bend test on CFRP composite specimen is performed at crosshead speed of 2 mm/min. The measured load-deflection response at mid-span location compares well with predicted values. Interface delamination accounts for up to 46.7 % reduction in flexural stiffness from the undamaged state. Delamination initiated at the center mid-span region for interfaces in the compressive laminates while edge delamination started in interfaces with tensile flexural stress in the laminates. Anti-symmetric distribution of the delaminated region is derived from the corresponding anti-symmetric ply sequence in the CFRP composite. The dissipation energy for edge delamination is greater than that for internal center delamination. In addition, delamination failure process in CFRP composite can be described by an exponential rate of fracture energy dissipation under monotonic three-point bend loading.