Rigid-Plastic Meso-damage Constitutive Model For Particle-Reinforced Composites And Its Application

A modified rigid-plastic meso-damage constitutive model for porouscomposites reinforced by rigid particles was suggested. The evolution lawsfor void and particles were introduced. The constitutive theory was used toanalysis the influences of void and particles on the strength and ductibility ofparticle-reinforced composites.To validate the reasonability and reliability of the rigid-plasiticmeso-damage constitutive theory, the numerical calculations based on theconstitutive theory were compared with the tensile experiments of Al matrixcomposites reinforced by SiC particles, The results show that the constitutivetheory agrees with the experimental stress-strain curves, which means that theconstitutive theory can be put into numerical simulation and predict themechanical properties of composites reinforced by rigid particles.Under the uniaxial stress state and uniaxial strain state respectively, thechanges of the composite's strength and toughness caused by the difference ininitial void volume fraction and initial particle volume fraction, as well astheir evolutions, were systematically studied. The two physical parameters, i.e.the effective stress, that could scale the strength, and the generalizedtriaxiality function, that could reflect the ductility of the composites, werediscussed in details. These results may guide the production and process ofthe composite reinforced by particles. The constitutive model was embedded in the rigid-plastic finite elementprogram. Based on the FEM program, the process of round board shaping wassimulated. The distributions of the effective strain, effective stress,generalized triaxiality function, etc.were derived. The FEM analyses wereconsistent with the results in practice.The constitutive model was simple relatively and was convenient to becombined with FEM program and applied in the practical engineeringstructures.