Modelling and damage evaluation of glass fiber-reinforced aluminium laminates subjected to quasi-static indentation

The present work involves a finite element simulation of Glass-reinforced aluminium laminate (GLARE) subjected to quasi-static loading to predict the damage modes using a cohesive zone model (CZM) while considering frictional effects between interfaces as well as indentor and laminate. The CZM, which involves cohesive elements and cohesive surface accompanied with frictional effect is the novelty of the work. Considering frictional effects at every dissimilar interfaces such as Al and composites as well as between the indentor and the surface of the laminate improves the accuracy of the damage prediction. Also, the addition of the in-plane failure modes of the composite in the GLARE laminate using continuum shell element, enabled us to study the combined effect between in-plane damage and out-of-plane delamination simultaneously. The response of CZM was governed by bilinear traction separation law to predict the initiation of damage based on quadratic failure criterion and evolution of damage was predicted based on mixed mode B-K criteria, which used a linear function of average through-thickness stresses. Prediction of plasticity, ductile and shear modes for damage of  the aluminium alloy were obtained by using Johnson–Cook and shear criteria respectively. Initiation of failure of the  composites were predicted by Hashin damage criteria. While the damage evolution of aluminium and composite were predicted using fracture toughness applying linear softening behaviour. A finite element model was developed based on the crack band theory and viscous regularization scheme respectively using the commercially available Abaqus/Explicit finite element solver. The experimentally obtained force versus displacement (F-D) curves for the quasistatic loading were analysed, to obtain the type and sequence of the damage. The FE simulation predicted results for type and sequence of damage which were compared with experimental results. Considering the frictional effect resulted in high delamination at the bottom layers and less delamination at the top layer as compared with prediction without frictional effect which is better prediction with experimental results. In addition, the extent of the damage was investigated using ultrasonic A and C-scan techniques. The numerical and experimental results in terms of F-D curves, size and shape of the delamination were found to be in good agreement.