TWO-PHASE CONSTITUTIVE MODELFOR THE ANALYSIS OF NONLINEARDEFORMATION OF WOVEN POLYMERMATRIX COMPOSITE

This study focuses on developing a material model for describing nonlinear deformation of composite materials in finite element analysis. The proposed approach is an extension of the previously presented multiphase constitutive model for fabric composite. The model tacking into account irreversible plastic deformations of the polymer matrix, scattered microdamage and fibre rotation of the fabric yarns. The model was implemented using UPF module in ANSYS Mechanical FEM package. Standard tensile and shear tests, as well as single-element models simulating simple loading cases, were used to determine and calibrate the model parameters The model’s performance was verified using static test results for fabric carbon fibre-reinforced plastic (CFRP) specimens with symmetrical lay-ups, as well as specimens cut at different angles to the warp direction. It was found that the proposed approach allows for describing the loading process and predicting composite strength under plane stress state with an error of no more than 15% for lay-ups with a small nonlinear matrix deformation (0°, ±15°, and ±30°). For lay-ups with pronounced deformation nonlinearity (30° and 45°), the model correctly predicted the stress-strain diagram of the CFRP specimen up to 5% of axial strain.