Accession Number : ADA295187

Title :   A Computational Model for Progressive Damage and Failure of Fiber-Reinforced Ceramic Composites.

Descriptive Note : Final rept. 12 Jul 94-12 Jan 95,

Corporate Author : MATERIALS AND SYSTEMS RESEARCH INC SALT LAKE CITY UT

Personal Author(s) : Chao, Luen-Yuan ; Shetty, Dinesh K.

PDF Url : ADA295187

Report Date : FEB 1995

Pagination or Media Count : 56

Abstract : A computational model was developed to simulate the progressive damage of fiber-reinforced brittle matrix composites under uniaxial tensile loading. In conjunction with the basic material properties, this model used a size-distribution of the 'fiber-free zones' as an input for the development of small penny-shaped cracks at the early stage of loading. Stable extension of such non-steady-state cracks and the transition from non-steady-state to steady-state cracks were modeled using a stress-intensity formulation for a partially-bridged penny-shaped crack. Stress-strain relation was simulated by calculating the total engineering strain in the gage section as a function of the applied stress. Strain energies of the non-steady-state cracks and displacements of the fibers in the sliding zones of the steady-state cracks were calculated to estimate the total strain. Two unidirectional fiber-reinforced composites were investigated to test the predictive capability of this model. The stress-strain relation predicted by the model was in good agreement with that measured experimentally for a SiC-reinforced calcium aluminosilicate composite. A SiC-reinforced magnesium aluminosilicate composite showed less cumulative strain before fracture due to premature fiber failure. (MM)

Descriptors :   *CERAMIC MATRIX COMPOSITES, *FIBER REINFORCED COMPOSITES, *CERAMIC MATERIALS, *FAILURE(MECHANICS), STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, MAGNESIUM, TENSILE STRESS, CRACKING(FRACTURING), DAMAGE ASSESSMENT, DISPLACEMENT, MATRIX MATERIALS, FRACTURE(MECHANICS), DEFECTS(MATERIALS), BRITTLENESS, STRAIN GAGES, SILICON CARBIDES, AXIAL LOADS.

Subject Categories : Ceramics, Refractories and Glass
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE