Accession Number : ADA310429

Title :   Micromechanical Model of Crack Growth in Fiber Reinforced Ceramics.

Descriptive Note : Final rept.,

Corporate Author : TULANE UNIV NEW ORLEANS LA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Rubinstein, Asher A. ; Xu, Kang

PDF Url : ADA310429

Report Date : SEP 1990

Pagination or Media Count : 33

Abstract : A model based on the micromechanical mechanism of crack growth resistance in fiber reinforced ceramics is presented. The formulation of the model is based on a small scale geometry of a macrocrack with a bridging zone, in this case the process zone, which governs the resistance mechanism. The effect of high toughness of the fibers in retardation of the crack advance, and the significance of the fiber pullout mechanism on the crack growth resistance, are reflected in this model. The model allows one to address issues such as influence of fiber spacing, fiber flexibility, and fiber-matrix friction. Two approaches were used. One represents the fracture initiation and concentrates on the development of the first microcrack between fibers. An exact closed form solution has been obtained for this case. The second case deals with the development of an array of microcracks between fibers forming the bridging zone. An implicit exact solution is formed for this case. In both cases, a discrete fiber distribution is incorporated into the solution.

Descriptors :   *CERAMIC MATERIALS, *CRACK PROPAGATION, *MICROMECHANICS, *FIBER REINFORCEMENT, STRESSES, FIBERS, MODELS, PROCESSING, GROWTH(GENERAL), RESISTANCE, FORMULATIONS, TOUGHNESS, MATRIX MATERIALS, FRACTURE(MECHANICS), DISCRETE DISTRIBUTION, GEOMETRY, FRICTION, RETARDATION, MICROCRACKING.

Subject Categories : Ceramics, Refractories and Glass
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE