A direct prediction method for 3D woven composites bending properties based on unit-cell finite element model

The deformation distribution along the thickness direction of 3D woven composites under bending loading is inhomogeneous, and hence there is difficulty in numerically predicting the bending behavior of woven composites. This paper aims to propose a direct mesoscopic method for predicting the bending behavior of woven composites using the unit-cell finite element model. Firstly, four-point bending tests were conducted in the warp and weft directions, respectively. Then, the periodic boundary conditions are established for the unit-cell model with non-uniformly distributed deformations under pure bending loading. Finally, the bending properties and damage accumulation process of the woven composites are analyzed based on the elasto-plastic damage model with different mechanical properties in tension and compression. The simulated moment-curvature curves and failure modes are in good agreement with the experimental results. It is shown that the developed unit-cell finite element model can accurately predict the bending behavior of woven composites.