INCORPORATING FIBER DAMAGE IN A MICROMECHANICAL ANALYSIS OF METAL-MATRIX COMPOSITE LAMINATES

A micromechanics based formulation involving me method of cells is dev eloped to analyze metal matrix composite behavior in the presence of f iber fragmentation. The effects of fiber fracture are accounted for by determining an instantaneous effective fiber modulus from a modified chain-of-bundles approach. The analysis assumes a uniform density of f iber breakage throughout the composite. This crack density is determin ed from Weibull statistics whose parameters may be obtained from singl e-fiber tests or estimated. The ultimate strength of titanium-based me tal matrix composite (MMC) laminates as well as their inelastic stress -strain response in the presence of fiber fragmentation are predicted from the present analysis which are in good agreement with the experim ental counterparts. Also, the applicability of the present analysis to predict the low cycle/high stress fatigue lives of MMC laminates is d emonstrated.