Simplified FE model and experimental study on the tensile properties of the glass fiber reinforced polyester polymer.

This research aims to understand the simplified finite element (FE) model behavior for estimating the glass fiber reinforced polyester polymer (GFRP) structural response and studying its tensile properties. The simplified FE model has been developed using an equivalent single-ply transversely isotropic material model to estimate the multi-layer GFRP laminates tensile behavior. The linear elastic and a trilinear plasticity material formulation were adopted. The experimental study is conducted to determine the tensile properties of the equivalent single-ply model of the multi-layer laminates with the variation of layers number, stacking sequence, and fiber orientation. The tensile test specimen used E-glass fiber reinforcement and polyester resin (Yukalac 157 BQTN-EX) as the matrix. The hand layup method was used for the lamination procedure. The experimental results show that the nonlinearity might occur due to the imperfection and poor quality of the composite laminate. Therefore, the comparison of numerical simulation and the experimental results is conducted to understand the stress-strain behavior of the simplified FE model. Both models presented different characteristics and showed good agreement with the experimental results. The linear model can be adopted while the nonlinearity is not significantly identified. Furthermore, the plastic strain as a compensated constant should be defined thoroughly to conduct an accurate estimation using the trilinear plasticity model. However, neither model is suitable for predicting the composite laminate's initial failure point.