Accession Number:

ADA238797

Title:

Effect of Thermal Residual Stresses on the Stress-Strain Behavior of Metal-Matrix Composites

Descriptive Note:

Master's thesis

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1990-09-01

Pagination or Media Count:

72.0

Abstract:

A parametric study was conducted to assess the effect of thermal residual stresses on the stress-strain response of a fiber-reinforced metal- matrix composite. The material chosen for investigation was silicon carbides whisker reinforced Al 6061 system. The effects of fiber volume fraction, fiber aspect ratio and fiber spacing were analyzed within the framework of axisymmetric finite element models to determine the overall constitutive response of the composite materials as well as to solve for local field quantities in the fiber and matrix. The composite was modeled as a periodic array of cylindrical fibers, laterally aligned in one model and staggered in the other. Perfect interfacial bonding and complete fiber alignment with the tensile axis were assumed. The results indicated that 1 composite stiffness, yield strength and work hardening rate increased with increasing volume fraction and fiber aspect ratio and 2 variations in fiber spacing primarily affect work hardening rate and have negligible effect on composite stiffness. It was found that the presence of residual stresses affected the stress-strain behavior of the composite by influencing the load transfer characteristics between the matrix and fiber as well as the initiation and growth of plastic deformation in the matrix.

Subject Categories:

  • Laminates and Composite Materials
  • Inorganic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE