Accession Number:

ADA242748

Title:

Damage Mechanisms in Composites

Descriptive Note:

Final technical rept.

Corporate Author:

BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING

Personal Author(s):

Report Date:

1991-08-01

Pagination or Media Count:

42.0

Abstract:

Mechanically induced residual stresses are an inherent feature of permanently deformed metal-matrix composites such as aluminum silicon carbide. The presence of hard SiC reinforcements promotes non homogeneous flow in the matrix, resulting in residual stresses when the applied loads are removed. These residual stresses are potentially important because of the effect on cavitation and other damage mechanisms leading to composite failure. We have attempted to simulate the residual stresses in the composite by solving appropriate boundary value problems using finite element method. Using this approach, we have compared predicted average residual elastic strains with those measured by neutron diffraction for Al SiC composites subjected to different loading histories. The composite studied was a 2009 aluminum alloy reinforced with 15 vol SiC whiskers. Samples were subjected to various levels of plastic strain and unloaded before measuring peak shifts in neutron diffraction patterns to determine residual strains.

Subject Categories:

  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE