Simulation Study for Temperature-Dependence of Tensile Strength of Continuous and Discontinuous Unidirectionally Fiber-Reinforced Metal Matrix Composites

Abstract

To describe the feature that the tensile strength of unidirectional discontinuous fiber (whisker)-reinforced aluminum matrix composites decreases with increasing temperature more than that of continuous fiber-reinforced ones, a calculation of the critical length and stress concentration factor affected by the temperature-dependence of mechanical property of matrix, and a Monte Carlo simulation, were carried out. The reduction in strength of both continuous and discontinuous fiber-composites at high temperatures could be attributed to the predominancy of the effect of the matrix-softening-induced increase in critical length over the effect of the decrease in stress concentration arising from the existence of fiber-ends and fiber-breakages. The larger reduction in strength of discontinuous fiber-composites at high temperatures than that of the continuous ones could be explained from the view-point of the larger reduction in the stress carrying capacity of fibers and easier fiber-pull-out.