Cohesive Zone Parameters Selection for Mode-I Prediction of Interfacial Delamination

Abstract

In order to determine the normal cohesive strength of composite laminates, a new test methodology was proposed. The values of cohesive zone parameters (the cohesive strength and the separation energy) for mode I interlamiar fracture of E-glass/epoxy woven fabrication were computed from a series of experimental tests. Cohesive zone model simulation based on interface finite elements was conducted. A modified form of the Park-Paulino-Roesler (PPR) traction-separation law together with a bilinear mixed-mode damage model was used to simulate the damage processes, using Abaqus cohesive elements. The numerical results were compared with experimental tests and confirmed the adequacy of normal cohesive strength. To ensure the sufficient dissipation of energy that successfully predicts delamination onset and propagation, cohesive zone length and minimum number of cohesive elements at cohesive zone length were determined. Interfacial penalty stiffness and the resistance curve of the composite specimen were also computed. The results show that the modified PPR model accurately simulates the fracture process zone ahead of the crack tip as compared to the bilinear model.

Modelling and Simulation of Impedance-Based Damage Monitoring of Structures

“…Results from the simulation and experiments showed that the damage metrics were affected by the longitudinal distance from the sensor location and its orientation. Moslemi and Khoshravan [3] proposed a methodology for the delamination characterization of composite laminates under pure Mode I. Different methods of determining the damage index were presented by Azhdary and Shabakhty [4].…”

Numerical and Experimental Research on Delamination of Glulam Elements

“…Parameters for glue layer were determined basing on guidelines about multi-layer composites, available in the literature. Cohesive zone delamination model in mode I and mode II was described in many publications, including [17][18][19]. According to these papers and authors' analyses in publication [20], cohesive zone parameters should be defined as follows.…”

Numerical model of glulam beam delamination in dependence on cohesive strength

“…To provide proper elements failure, the following conditions for elements length in each fracture mode should be met [7,8]: …”