An improved orthotropic elasto-plastic damage model for plain woven composites

A ply based non-linear material constitutive model for plain woven (PW) composite, with provision to decouple the effect of plasticity and progressive damage as observed in experiments, is proposed. Mechanical characterization of basalt plain woven (BPW) is performed to evaluate the elastic moduli and strengths, intralaminar and interlaminar fracture energies whereas non-linear behavior was obtained via off-axis tests and Iosipescu test which are not available in literature yet. The single parameter plasticity potential function of Sun and Chen (1989) is modified in terms of effective stress and relation between effective flow stress and equivalent strain is determined from cyclic tests. The separation of plasticity and damage in writing the latter relation is often ignored by researchers in absence of cyclic loading experimental data. The material properties obtained were used as an input for VUMAT sub-routine which was implemented in ABAQUS to simulate the low velocity impact (LVI) phenomenon at three different impact energies and was able to successfully predict force, deflection and absorbed energy response. The accurate prediction of indentation depth and diameter leads to better understand the behavior of the indent region which is formed due to the major contribution of out of plane plastic strains and damage modes.