Finite element micromechanical analysis of the deformation and stress state dependent damage evolution in fiber reinforced metal matrix composites

The progression of ductile damage evolution in the metal matrix and the macroscopic deformation behavior of fiber-reinforced metal matrix composite were investigated using an Internal State Variable (ISV) plasticity-damage model implemented in finite element code. The material properties of the fibers were set as those of Boron while the material properties or behavior of the metal matrix matched those of 99% pure aluminum. The influences of the fiber arrangement and the interphase stiffness on the damage evolution and transverse macroscopic behavior were analyzed. The finite element simulations were terminated when the first element failure occurred. The simulation results show that the void grew as the stress triaxiality increased. After the volume fraction of the fibers increased up to moderate value (about 40%), the fiber square array exhibited much stronger strengthening effects than that of fiber hexagonal array. The damage evolution, in the case of the weak interphase, was studied as well.