Interlaminar fracture toughness of GLARE laminates based on asymmetric double cantilever beam (ADCB)

Interlaminar fracture toughness of GLARE laminates (Glass reinforced aluminum laminates) with different fiber orientation, such as cross-plies/0 degrees and unidirectional-plies/0 degrees, were investigated by the combination of experiments and finite element analyses. The Beam Theory and Fracture mechanics theory were used to calculate the proportion of Mode I and Mode II and further to predict the interlaminar fracture toughness of GLARE laminates. Also, the effect of loading rates (1 mm/min, 5 mm/min and 10 mm/min) on the interlaminar fracture properties was studied. Finite element analyses were carried out based on cohesive zone model (CZM) to numerically simulate delamination propagation by using the above experimental G(IC). The results showed that the inter laminar fracture toughness in cross-plies/0 degrees laminates(0.248 kJ/m(2)) was higher than that in unidirectional-plies/0 degrees laminates(0.093 kJ/m(2)), and the interlaminar fracture toughness was increased with the growth of the loading rates. The numerical results agreed well with the experiments at crack initiation and furthermore supported the absence of mode mixity. The deviation between theoretical calculations and experimental results gradually increased with the crack propagation. Meanwhile, they were conformed to the linear function for unidirectional-plies/0 degrees and cross-plies/0 degrees laminates, respectively. Besides, the experimental data are highly consistent with both theoretical calculation and numerical simulation results.