INTERFACE EFFECTS ON THE MICROMECHANICAL RESPONSE OF A TRANSVERSELY LOADED SINGLE-FIBER SCS-6 TI-6AL-4V COMPOSITE/

Citation
Sg. Warrier et al., INTERFACE EFFECTS ON THE MICROMECHANICAL RESPONSE OF A TRANSVERSELY LOADED SINGLE-FIBER SCS-6 TI-6AL-4V COMPOSITE/, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 27(7), 1996, pp. 2035-2043
Citations number
42
Categorie Soggetti
Metallurgy & Metallurigical Engineering","Material Science
ISSN journal
10735623
Volume
27
Issue
7
Year of publication
1996
Pages
2035 - 2043
Database
ISI
SICI code
1073-5623(1996)27:7<2035:IEOTMR>2.0.ZU;2-Q
Abstract
The ability of a fiber-matrix interface to support a transverse load i s typically evaluated in straight-sided composite specimens where a st ress singularity exists at the free surface of the interface. This str ess singularity is often the cause of crack initiation and debonding d uring transverse loading. In order to develop a fundamental understand ing of the transverse behavior of the fiber-matrix interface, it is ne cessary to alter the crack initiation site from the free surface to an internal location. To achieve this objective, a cross-shaped specimen has been recently developed. In this study, based on the experimental ly observed onset of nonlinearity in the stress-strain curve of these specimens and finite element analysis, the bond strength of the SCS-6/ Ti-6Al-4V interface was determined to be 115 MPa. The micromechanical behavior of these specimens under transverse loading was examined by f inite element analysis using this interface bond strength value and co mpared with experimental observations. Results demonstrate that the pr oposed geometry was successful in suppressing debonding at the surface and altering it to an internal event. The results from numerical anal ysis correlated well with the experimental stress-strain curve and sev eral simple analytical models. In an attempt to identify the true bond strength and the interface failure criterion, the present study sugge sts that if failure initiates under tensile radial stresses, then the normal bond strength of the SCS-6/Ti 6Al-4V composites is about 115 MP a; under shear failure, the tangential shear strength of the interface is about 180 MPa.