Dynamic constitutive-micromechanical model to predict dynamic shear behavior of glass/epoxy composites

Due to the wide applications of polymeric materials, it is necessary to develop a dynamic constitutive model to investigate their strain rate dependent mechanical behavior. In this study, the generalized strain rate dependent constitutive model was developed based on the experimental results of polymers. The experimental data of thermoset and thermoplastic polymers were used to evaluate the model. The present model includes three main components; the first component expresses the elastic stress-strain behavior of polymers. The second component models the nonlinear stress-strain behavior of the material using the Johnson-Cook model and the third component predicts the ultimate strength of polymers. Then, by combining the generalized strain rate dependent constitutive model and the plasticity micromechanical model of Huang, the shear behavior of glass/epoxy composites is predicted. This model, called dynamic constitutive-micromechanical model, removed dependency of composite mechanical behavior to the fiber volume fraction and the strain rate. Therefore, experimental characterization was reduced significantly. Finally, it was shown that the generalized strain rate dependent constitutive model and the dynamic constitutive-micromechanical model predicted the mechanical behavior of neat polymers and glass/epoxy composites respectively, with good accuracies .