Accession Number : ADA311316

Title :   Micromechanically Based Study of Localization of Deformation and Shear Bands Formation in Brittle Materials.

Descriptive Note : Final technical rept. 15 Aug 92-31 Dec 95,

Corporate Author : TUFTS UNIV MEDFORD MA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Kachanov, Mark

PDF Url : ADA311316

Report Date : 31 DEC 1995

Pagination or Media Count : 11

Abstract : Understanding of the phenomenon of localization requires Construction of micromechanically based constitutive equations for microcracking solids, involving a number of rather complex issues of the mechanics of multiple interacting defects. Therefore, the first pan of our efforts was concentrated on several key issues of micromechanics: stress induced anisotropy and the mechanics of multiple interacting microcracks in an anisotropic environment; mechanics of secondary ('winged') microcracks forming under compressive conditions; mechanics of intersecting cracks, both in two and three dimensional configurations; the impact of compressible fluid that saturates a geomaterial on the interaction effects. The second part of our effort was focused on localization of deformation and formation of shear bands in inhomogeneous brittle materials under compression The conditions of localization and formation of shear bands are very sensitive to the exact structure of constitutive equations, in particular, to the factors like violation of the normality rule, formation of a vertex on a loading surface, dilatancy and stress induced anisotropy. These issues have been examined.

Descriptors :   *FRACTURE(MECHANICS), *SHEAR STRESSES, *STRESS CONCENTRATION, BANDS(STRIPS), IMPACT, INTERACTIONS, DEFORMATION, CRACKS, DEFECTS(MATERIALS), BRITTLENESS, ANISOTROPY, MICROMECHANICS, COMPRESSIVE PROPERTIES, MICROCRACKING.

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE