The impact performance of laminated plain-woven fabric composites was analysed here using the elasto-plastic constitutive law, which can account for the anisotropic and asymmetric properties of fibre-reinforced plastics. The isotropic yield criterion was modified to account for the anisotropic and asymmetric initial yielding, while the kinematic hardening law with anisotropic evolution of back-stress was used for the anisotropic hardening behaviour. The impact tests were performed on laminated plain-woven composites. The simulation results for the impact tests compared well with experimental results.

A fabric is a flexible material that it is highly affected by its own weight, which causes large deflections. The relationship between the bending moment and the curvature is nonlinear. This study presents a model for fabric buckling by considering the flexibility of the fabric as well as its nonlinearity in bending. The bending rigidity of the fabric is considered to be a function of its curvature to take into account the fabric's nonlinear bending properties. Based on Timoshenko's elastica theory and the Bernoulli-Euler theorem, geometric nonlinearity is also taken into account. Kawabata pure bending test results are applied to the governing equation. The values from the model. are compared with the experimental data. The results show a clear distinction from the linear model, where the nonlinear method coincides well with the experimental values. From data evaluated by the numerical analysis method, the critical buckling load is calculated.

Impact analysis of 3D braided composites and laminated plane woven fabric composites was performed using the elasto-plastic constitutive law to describe the nonlinear, anisotropic and asymmetric properties of fiber-reinforced composites. As for the yield criterion, the modified Drucker—Prager yield criterion was utilized to represent the anisotropic and asymmetric properties, while the anisotropic hardening was described based on the kinematic hardening with the anisotropic evolution of the back-stress. Experiments to obtain the material parameters of the proposed constitutive law were also carried out based on uni-axial tension and compression tests for fiber-reinforced composites. Then, the proposed constitutive law was implemented into a finite element code and was verified by comparing the finite element simulation of the impact tests with experiments. In addition, impact performance of the braided composites and laminated composites was also compared with each other.