Elastoplastic compression constitutive behaviours and damage mechanisms of 3D4D braided FRP at temperatures of 25 °C and 85 °C

Distinct plastic plateau and nonlinear elastoplastic constitutive behaviours are substantiated in longitudinal and transverse compression tests on 3D4D braided fibre-reinforced polymer (FRP) at temperatures of 25 °C and 85 °C. A new nonlinear constitutive law is derived to depict elastoplastic compression constitutive behaviours of 3D4D braided FRP in view of thermo-mechanical interaction, elastoplastic nature of epoxy resin and nonlinear shear constitutive law of fibre yarn. A novel hybrid failure criterion is devised based on the Hashin, quad damage, von Mises and B-K energy rules for progressive failure modelling of 3D4D braided FRP. An original full-scale high-fidelity mesoscale finite element model is presented to simulate nonlinear elastoplastic compression behaviours and damage mechanisms of 3D4D braided FRP under the aforementioned loading and temperature conditions. Numerical simulations are consistent with experimental results, manifesting the effective and rational use of the proposed model.