Micro-mechanical simulation of longitudinal compression in composites considering stochastic fiber strength

Kink band is a typical phenomenon in longitudinal compression of composites. Numerical simulations considering fiber misalignment and plastic matrix with ductile damage have been built to study the formation of kink band. The matrix was simulated by using the extended Drucker-Prager constitutive model. Then random fiber strength distribution and stiffness reduction were considered to simulate the fiber break. The calculated critical stress and compressive modulus are consistent with experimental results. And the simulation results clearly reveal the longitudinal compressive damage process of the composites. It can be concluded that kink band formation and peak load rely on the matrix yielding. However, fiber properties including fiber misalignment, fiber volume fraction and fiber diameter do affect the kink band shape and compressive strength.