DAMAGE EVOLUTION IN Ti-SiC UNIDIRECTIONAL FIBER COMPOSITES, J.C. Hanan, G.A. Swift, E. Ustundag, I.J. Beyerlein, B. Clausen, J. Almer, U. Lienert, D.R. Haeffner, pp. 251-256

Fiber fractures in metal-matrix composites often initiate damage zones that grow until the composite fails. To better understand the evolution of such damage from a micromechanics point of view, a model Ti-matrix/SiC-fiber composite was studied for the first time. Using high energy X-rays and a small sampling volume, the damage zone around a broken fiber was investigated. The growth of this zone was monitored in situ under applied tensile stress by measuring the responses of the fibers and the matrix. The diffraction data was compared to a modified shear lag model, which considers the elastic response of the matrix and the fibers. A comparison of the model and data shows a correlation on the trend of the data, while the nature of the damage region incurs discrepancies. Results indicate a need for further refinement of the model, revealing the necessity of incorporating such factors as residual stress in the system and plasticity in the matrix.