Fiber reinforcement of metal matrices against plastic flow

The uniaxial stress-strain behavior and plastic flow in rate-independent pl astic flow for transverse loading of continuous fiber-reinforced metal-matr ix composites are examined in this paper. Cell models with different packin g arrangements are employed to analyze the effects of fiber cross-sectional shapes (square, circular, and diamond) and periodic distributions (square, hexagonal and diagonal packing arrays) as well as transverse loading direc tions (45 degrees, 0 degrees, or 90 degrees) on the transverse plastic defo rmation of metal-matrix composites reinforced with periodically distributed , aligned continuous fibers. Calculations were carried out using increasing ly refined meshes to demonstrate numerical convergence. The calculations of the alternations in matrix field quantities in response to controlled chan ges in the fiber packing array give insights into the effects of fiber clus tering on the transverse plastic flow. The results indicated that the overa ll transverse plastic flow of the composites is sensitive to fiber geometri c parameters, such as fiber shape, packing arrangement and volume fraction, and to the transverse loading direction. The stress contours demonstrated that the interference of fibers with flow paths plays an important role in the transverse strengthening mechanism. (C) Elsevier Science Inc., 1999. Al l rights reserved.