Accession Number:

ADA256782

Title:

Nonlinear Finite Element Analysis of Metals and Metal Matrix Composites: A Local-Global Investigation

Descriptive Note:

Technical rept.

Corporate Author:

PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB

Personal Author(s):

Report Date:

1992-10-01

Pagination or Media Count:

105.0

Abstract:

A computational investigation of the fracture mechanics of metals and metal matrix composites has been carried out. The ductile fracture of structural alloys was analyzed through a two dimensional non-linear finite element approach, while the mechanics of load transfer in silicon carbide SCS-6 fiber reinforced titanium alloy Ti-15V-3Cr-3Al-3Sn were studied using a local-global finite element analysis procedure. The computed values of the J-Integral for compact tension specimens of steel and aluminum alloys 0.533 or - aW or - 0.884 remain path independent up to a certain load which is attributed to crack initiation, and then diverge. There is a unique signature of the strain energy density dWdV ahead of the crack in the O deg direction the strain energy first decreases, reaches a minimum and then increases with increasing distance from the crack tip. The minimum strain energy shows a unique dependence on the applied load. This leads to the prediction of the fracture loads for the cracked specimens. A novel coordinate system rotation was employed in extracting the boundary conditions from the two-dimensional global model to the three- dimensional local model for the local-global finite element analysis of the unidirectional composite.

Subject Categories:

  • Laminates and Composite Materials
  • Properties of Metals and Alloys
  • Theoretical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE