EFFECT OF FIBER FRACTURE AND MATRIX YIELDING ON LOAD SHARING IN CONTINUOUS FIBER METAL-MATRIX COMPOSITES

This paper addresses the issue of stress redistribution in the presenc e of a fiber fracture in a composite lamina. Stress elevation in the f iber adjacent to the broken fiber is the focus of this study. The stre ss concentration effects in the vicinity of the fiber break and its in fluence on the neighboring intact fiber is analyzed using the finite e lement method as a function of fiber volume fraction. The role of the inelastic behavior of the matrix in causing the stress elevation is st udied. It is found that the state of stress in the intact fiber is aff ected significantly by the propagation of the plastic front due to mat rix yielding. The local stress field is affected also if the fiber bre ak is followed by interfacial debonding. Titanium matrix reinforced wi th continuous fibers of silicon carbide is chosen as the metal matrix composite system for this study. Experimental comparisons are made wit h tension tests conducted using a single-ply lamina.