Experimentally verified dual-scale modelling framework for predicting the strain rate-dependent nonlinear anisotropic deformation response of unidirectional non-crimp fabric composites

A new hierarchical dual-scale modelling framework is developed for predicting the strain rate-dependent nonlinear deformation response of a unidirectional non-crimp fabric (NCF) carbon fiber/snap-cure epoxy composite. A linear Drucker-Prager model that considers tension-compression asymmetry of the yield surface was used to capture the elastic-plastic response of the epoxy within the microscale finite element (FE) model, while randomly dispersed carbon fibers were treated as linear elastic. For the mesoscale FE model, the effective elastic-plastic response of the impregnated tow was modelled using Hill's anisotropic yield function. The postyield strain rate dependency of the epoxy and impregnated tow was captured with the Johnson-Cook model, with the former being calibrated using available experimental data. The predicted post-yield response of the impregnated tow was found to be dependent on the applied strain rate. An excellent agreement was observed between the predicted and experimentally measured stress-strain response for the NCF composite at quasi-static strain rates. The predicted in-plane and out-of-plane shear stress-strain responses revealed a strong dependence on the applied strain rate. The newly developed dual-scale modelling framework can be utilized as a tool to effectively predict the strain rate-dependent non-linear response for other fabric-reinforced composite material systems.

Automated summary

A new hierarchical dual-scale modelling framework is developed to predict the strain rate-dependent nonlinear deformation response of a unidirectional non-crimp fabric carbon fiber/snap-cure epoxy composite. The model considers tension-compression asymmetry and anisotropic yield function to accurately predict the stress-strain response.