Local field effects in titanium matrix composites subject to fiber-matrix debonding

Abstract

This paper addresses fiber-matrix debonding in titanium matrix composites (TMCs) using a recently developed micromechanics model known as the high-fidelity generalized method of cells (HFGMC). By employing a higher-order displacement field, this model supercedes its predecessor, the generalized method of cells (GMC), in terms of micro-scale field accuracy. The import of this micro-scale accuracy is amplified in the case of fiber-matrix debonding as the debonding phenomenon is dominated by local field effects. Via inclusion of appropriate constitutive relations for inelastic deformation and fiber-matrix debonding, both HFGMC and GMC have been applied herein to model the transverse deformation of titanium matrix composites, which exhibit obvious effects of interfacial debonding. Results indicate that HFGMC is considerably more quantitatively accurate than GMC for analysis of composites with debonding, enabling realistic predictions of the TMC transverse response. The improved accuracy of the HFGMC local fields also enables investigation of some qualitative aspects of the debonding phenomenon within TMCs.