Predicting the nonlinear tensile response of Glare 3

Tensile tests were carried out on GLARE® 3, a hybrid laminate made of foils of 2024-T3 aluminium alloy bonded together with unidirectional laminae of Glass Fibre Reinforced Plastics (GFRP), varying the fibre orientation with respect to the loading direction. The material response was clearly affected by the presence of both GFRP and aluminium, exhibiting a marked anisotropy and a highly non-linear behaviour before final failure. Simple hypotheses were adopted to model the stress-strain curve of aluminium and GFRP, and to analytically describe the failure conditions. The assumptions made were used together with lamination theory, to predict the overall stress-strain curve of the material. Comparing the theoretical results with the experimental data, it was found that the proposed method is able to calculate with sufficient accuracy the material behaviour. In particular the correlation between theory and experiments is satisfying for what concerns the elastic modulus and general trend of the stress-strain curve. However, some discrepancies are found when the tensile strength and the strain to failure are considered.