Analysis of Creep for Metal Matrix Composites

Abstract

The primary creep deformation of a unidirectional metal matrix com posite is analyzed. A continuum model is developed based on the results of experiments conducted on unreinforced and unidirectionally-reinforced aluminum. The experiments show that the longitudinal creep of Gr/Al is ef fectively inhibited by the fibers due to the extremely high elastic modulus and negligible creep properties of the latter. The transverse creep, however, is significant even at an applied stress level far below that necessary to cause creep in the unreinforced aluminum. Damage parameters, D T and D s , related to the inhomogeneous local distribution of transverse and shear stresses, respectively, and the initial residual stress, σ R are shown to account for the observed behavior quite satisfactorily.