A Multiscale Modeling Methodology for Metal Matrix Composites Including Fiber Strength Stochastics
A multiscale modeling methodology was developed that incorporates a statistical distribution of fiber strengths into coupled micromechanics / finite element analyses. A parametric study using the NASA Micromechanics Analysis Code with the Generalized Method of Cells was performed to assess the effect of variable fiber strengths on global composite failure at the repeating unit cell level. The NASA code FEAMAC and the ABAQUS finite element solver were used to analyze the progressive failure of a metal matrix composite tensile dogbone specimen. A statistical distribution of fiber strengths based upon a two parameter Weibull cumulative distribution function was assigned to individual repeating unit cells corresponding to element integration points within ABAQUS. Multiple analyses were performed to quantify the effect of randomly varying fiber strengths on the temperature-dependent composite stress-strain response and local failure. By including a random distribution of fiber strength in micromechanical calculations that feed into a global finite element framework, distributed failure occurs in the specimen more consistent with experimental observation. 2012 AIAA.