Date of Award

12-1992

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Aeronautics and Astronautics

First Advisor

Anthony N. Palazotto, PhD

Abstract

Experimental and computational analyses provided an improved understanding of quasi-static fracture in model composite systems. Constant displacement compression tests using borosilicate glass double cleavage drilled compression test templates provided qualitative assessments of localized toughening for crack growth near cylindrical inclusions. Large crack-tip stress fields induced interfacial slip and separation prior to arrival of the main crack. Debonding and the proliferation of secondary matrix cracks characterized the role of bridging fibers along weak interfaces. Strong residual normal compressive interfacial stresses diminished the influence of crack-tip stresses; however, slip was still observed. VHS tape and computer enhanced photos record a history of crack propagation and interfacial slip. Experimental data was used to validate a fully three-dimensional computational code capable of analyzing fracture near and around cylindrical inclusions. Consistent variations in the shape of the crack periphery renders confidence in the elasticity solution.

AFIT Designator

AFIT-GAE-ENY-92D-04

DTIC Accession Number

ADA258913

Comments

The author's Vita page is omitted.

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