Senior scientist, FAA Technical Center, Atlantic City International Airport, Atlantic City, NJ
Professor, University of Cairo, Cairo,
Research scientist, Analytical Services and Material, Hampton, VA
Pages: 19 Published: Jan 1996
A three-dimensional finite element program called VISCOPAC was developed and used to conduct a micromechanics analysis of titanium metal matrix composites. The VISCOPAC program uses a modified Eisenberg-Yen thermo-viscoplastic constitutive model to predict matrix behavior under thermomechanical fatigue loading. The analysis incorporated temperature-dependent elastic properties in the fiber and temperature-dependent viscoplastic properties in the matrix. The material model was described and the necessary material constants were determined experimentally. Fiber-matrix interfacial behavior was analyzed using a discrete fiber-matrix model. The thermal residual stresses due to the fabrication cycle were predicted with a failed interface. The failed interface resulted in lower thermal residual stresses in the matrix and fiber. Stresses due to a uniform transverse load were calculated at two temperatures, room temperature and an elevated temperature of 650°C. At both temperatures, a large stress concentration was calculated when the interface had failed. The results indicate the importance of accurately accounting for fiber-matrix interface failure and the need for a micromechanics-based analytical technique to understand and predict the behavior of titanium metal matrix composites.
thermal residual stresses, interface, finite element analysis, viscoplasticity, discrete fiber-matrix model, titanium, titanium matrix composites, life prediction, titanium alloys, fatigue (materials), modeling
Paper ID: STP18228S