Study on longitudinal tensile properties of SiC_f/Ti-6Al-4V composites with different interfacial shear strength

摘要

Effect of interfacial shear strength on longitudinal tensile properties for SiC_f/Ti-6Al-4V composites is investigated by Monte Carlo finite element method. A two-parameter Weibull function is employed to describe random distribution of fiber strength. Fiber breakage, matrix cracking and interfacial debonding are simulated by killing the element when stress applied to element exceeds corresponding strength and releasing coupled nodes when shear stress exceeds shear strength at interfaces. The results show that tensile strength of SiCf/Ti-6Al-4V composites keeps unchanged for various interfacial shear strengths, but low interfacial shear strength is advantageous to reduce catastrophic failure. Moreover, with low interfacial shear strength, fiber breakage in the composites is more inclined to be non-coplanar. In addition, tensile strength obtained from finite element method is compared with those predicted by global load-sharing model (GLS), local load-sharing model (LLS) and conventional rule of mixtures (ROM) and is identical with that obtained from LLS.