Micromechanical Modeling of Fiber Composites Under Off-Axis Loading

Abstract

The nonlinear behavior of AS4/PEEK composite under off-axis loading was investigated using a finite element-based micromechanical approach with three different unit cells. Proper boundary conditions for uniaxial off-axis loading for the unit cell were established. The elastic moduli of the fiber and the nonlinear stress-strain curve of the matrix were used in the micromechanical analysis. By comparing the predicted off-axis stress-strain curves with experimental data, it was found that the nonlinear behavior of the composite is highly dependent on the fiber packing arrangement of the unit cell model.