A NUMERICAL-SIMULATION OF THE EFFECTS OF VOLUME FRACTION, CREEP AND THERMAL CYCLING ON THE BEHAVIOR OF FIBROUS METAL-MATRIX COMPOSITES

A previously derived cyclic neutral thermoviscoplasticity theory for fibrous metal-matrix composites (Yeh and Krempl [1]), which combines the vanishing fiber diameter (VFD) model with the thermoviscoplasticity theory based on overstress (TVBO) is specialized for transversely isotropic, thermoelastic fibers and an isotropic, thermoviscoplastic matrix. Numerical experiments are used to illustrate the predictive capability of the theory. Simulations include die influence of volume fraction on the monotonic and cyclic loading behavior in the fiber and transverse directions with creep holds for B/Al and B/Ti unidirectional composites and thermal cycling of B/Al. The three-dimensional theory permits the calculation of the actual Poisson's ratio in the tests. The results compare favorably with sparsely available experimental results.