TRANSVERSE YIELDING AND MATRIX FLOW PAST THE FIBERS IN METAL-MATRIX COMPOSITES

This paper examines the plastic flow in transverse loading of metal matrix composites reinforced with well bonded continuous fibers when stress gradients are developed so that the matrix not only yields but also Rows past the fibers. The fibers are stationary due to elastic constraint as would occur, for example, in a circumferentially reinforced ring. The matrix is elastic perfectly plastic, The study is performed using cell models. Results are given for the influence of the fiber volume fraction, fiber arrangement and stress gradients. The yield surface in terms of mean stress and stress gradient is calculated from this analysis, It is found that the transverse limit strengths are sensitive to the transverse stress gradient across the cell. In addition, a constitutive relationship accounting for matrix plastic straining and matrix Row past the fibers is developed.