Analysis of cohesive zone model parameters on response of glass-epoxy composite in mode II interlaminar fracture toughness test
Konrad Dadej, Barbara Surowska
Quarterly No. 3, 2016 pages 180-188
DOI:
keywords: interlaminar fracture toughness, mode II, cohesive zone method, numerical modelling
abstract The purpose of the performed study was to provide the best possible representation of the response of a beam subjected to Interlaminar Fracture Toughness testing in Mode II in the course of the End Notched Flexure test. The beam was modelled numerically with the results obtained in experimental tests. Furthermore, analysis was carried out in order to determine the parameters of the traction-separation law in the ABAQUS program defined for the cohesion layer, which have a key impact on the response of the cracking composite beam in the End Notched Flexure test. Experimental tests were conducted on composite beams reinforced with 'E' type fibre glass in an epoxy resin matrix. A composite plate 4.3 mm thick produced in the autoclave process was cut into beams with dimensions of 150 x 25 mm in a manner ensuring an initial delamination length of 30 mm. A numerical model of the composite material with a cohesion layer based on the determined value of fracture energy in Mode II was developed in the ABAQUS program on the basis of experimental tests. The analysis of the impact of the parameters defined in the traction-separation law on the response of the cracking composite beam was conducted on the basis of numerical simulations. The results obtained from the numerical analyses show a strong dependence between the cohesion layer parameters and the response of the composite beam, also in case of a constant value of fracture toughness. It was determined which of the parameters defined in the ABAQUS program have a key impact on the composite cracking process. Finally, very good convergence was achieved for the beam response in the numerical model and in the experiment in terms of force-displacement curves, the critical value of force and displacement causing energy release and crack length in the composite.