Accession Number : AD0719934

Title :   An Investigation on the Crack Arrest Capability of a Hole.

Descriptive Note : Technical rept.,

Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Kobayashi,A. S. ; Wade,B. G. ; Maiden,D. E.

Report Date : JAN 1971

Pagination or Media Count : 27

Abstract : Dynamic photoelasticity by a 16-spark gap Cranz-Schardin camera system was used to determine some of the conditions leading to fracture arrest by a circular hole ahead of a propagating crack. Photoelastic models of 3/8 in. x 10 in. x 10 in. Homolite-100 plates with a 1/2 inch edge crack were loaded in a fixed grip configuration and crack arrest was achieved by central holes of 1/2, 1/4, and 1/8 inch diameters. For a uniformly loaded plate, with a central hole of 1/8 inch diameter, the propagating crack continued through this hole. Changes in dynamic stress intensity factors, as the crack tip approaches the hole, as well as changes in the dynamic stress concentration factors at the far side of the hole were studied and these results were compared with the corresponding static results determined by finite element analysis. This comparison shows that the static analysis can be used to qualitatively asses the arrest capability of the hole using the maximum static stress concept or the proposed concept of strain energy released as the crack penetrates the hole. (Author)

Descriptors :   (*METAL PLATES, *FRACTURE(MECHANICS)), (*CRACK PROPAGATION, PHOTOELASTICITY), ORIFICES, STRESSES, STRAIN(MECHANICS), SHIP HULLS, AIRPLANE PANELS

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE