Accession Number:

ADB177723

Title:

The Mechanics of Delamination in Fiber-Reinforced Composite Materials. Part 2. Delamination Behavior and Fracture Mechanics Parameters

Descriptive Note:

Contract rept.

Corporate Author:

ILLINOIS UNIV AT URBANA DEPT OF THEORETICAL AND APPLIED MECHANICS

Personal Author(s):

Report Date:

1983-11-01

Pagination or Media Count:

61.0

Abstract:

Based on theories of laminate anisotropic elasticity and interlaminar fracture, the complete solution structure associated with a composite delamination is determined. Fracture mechanics parameters characterizing the interlaminar crack behavior are defined from asymptotic stress solutions for delaminations with different crack-tip deformation configurations. A numerical method employing singular finite elements is developed to study delaminations in fiber composites with any arbitrary combinations of lamination, material, geometric, and crack variables. The special finite elements include the exact delamination stress singularity in its formulation. The method is shown to be computationally accurate and efficient, and operationally simple. to illustrate the basic nature of composite delamination, solutions are shown for edge- delaminated and graphite-epoxy systems under uniform axial extension. Three- dimensional crack-tip stress intensity factors, associated energy release rates, and delamination crack-closure are determined for each individual case. the basic mechanics and mechanisms of composite delamination are studied, and fundamental characteristics unique to recently proposed tests for interlaminar fracture toughness of fiber composite laminates are examined. Influences of lamination, geometric, and crack variables on the delamination behavior are investigated.

Subject Categories:

  • Adhesives, Seals and Binders
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE