A new approach to the elastic-plastic stress transfer analysis of metal matrix composites

摘要

An analytical approach is proposed for studying the elastic-plastic behavior of short-fiber-reinforced metal matrix composites under tensile loading. In the proposed research, a micromechanical approach is employed, considering an axisymmetric unit cell including one fiber and the surrounding matrix. First, the governing equations and the boundary conditions are derived and the elastic solution is obtained based on some shear-lag-type methods. Since under normal loading conditions and according to the fiber material characteristics, the metal matrix undergoes plastic deformation, while the fiber remains within the elastic region, a plastic deformation is considered for the matrix under each small tensile loading step. Then, applying the successive elastic solutions method, all the plastic strain terms are obtained for the matrix. Thereafter, the elastic-plastic stress transfer behavior of the composite is studied considering this plastic deformation. The results are finally compared with the numerical results obtained from the FE analysis of the considered micromechanical model. The proposed method is capable of predicting all plastic strain terms in the matrix and the stress terms, as well.