Accession Number:

AD0619199

Title:

A MECHANISM FOR THE CONTROL OF CRACK PROPAGATION IN ALL-BRITTLE SYSTEMS,

Descriptive Note:

Corporate Author:

EXPLOSIVES RESEARCH AND DEVELOPMENT ESTABLISHMENT WALTHAM ABBEY (ENGLAND)

Personal Author(s):

Report Date:

1964-03-19

Pagination or Media Count:

19.0

Abstract:

The stress distribution close to the tip of a crack which has a finite tip radius and which is being opened either by means of a remotely applied tension field sigma suby,0 or by means of a concentrated force e.g. a wedge driven into the crack has been computed. It is shown that there exist tensile stresses sigma sub x parallel to the plane of the crack and ahead of the crack tip. The maximum value of the tension sigma sub x is an approximately constant fraction about 15 of the peak stress concentration sigma suby, max which usually causes crack propagation. Inside a brittle solid, if a plane of weakness or potential cleavage is present and is roughly normal to the plane of the original crack, this interface may break and produce a secondary crack in such a manner as to interfere with the progress of the primary crack. If the ratio of the adhesive strength of the interface to the general cohesive strength of the solid is in the right range large increases in the strength and toughness of otherwise brittle solids may result. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE