Accession Number : ADA291131

Title :   Stress Intensity Factors and Crack Mouth Openings for Bridged Cracks Emanating from Circular Holes,

Corporate Author : DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)

Personal Author(s) : Pickthall, C. R.

PDF Url : ADA291131

Report Date : JUL 1994

Pagination or Media Count : 69

Abstract : Muskhelishvili's method of complex potentials has been applied to the problems of one crack, and two diametrically opposed (symmetrical) cracks emanating from a circular hole of radius R, subjected to a biaxial load. The cracks of length a, are orthogonal to the principal applied stress omega, with transverse stress omega = lambda/omega.This work extends previous work through the inclusion of linear springs with spring constant k bridging the crack opening. Analysis focussed on the (normalized) design parameters of crack tip stress intensity factor F(n) and crack mouth opening V(n). Their dependencies on biaxiality lambda, normalized spring stiffness ka, and the geometry specified by a/n = a/(a + R), were investigated. Interpolation formulae with parameters depending on were fitted to the high and low ka limits of F(n) and V(n). These provided a simple means for calculating F(n) and V(n), in most cases to within a few percent of the numerically calculated values. An interesting comparison of the symmetrically cracked hole to the partially bridged centre crack, showed that the latter had a lower stress intensity factor in all but the very short crack cases. (AN)

Descriptors :   *CRACKING(FRACTURING), *STRESS CONCENTRATION, STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, STRESS ANALYSIS, SHEAR MODULUS, STIFFNESS, INTENSITY, DISLOCATIONS, HOLES(OPENINGS), APPROXIMATION(MATHEMATICS), INTERPOLATION, TENSION, BIAXIAL STRESSES, INTEGRAL EQUATIONS, AUSTRALIA, FATIGUE TESTS(MECHANICS), AXIAL LOADS, BRIDGES, FORMULAS(MATHEMATICS), LOW INTENSITY, COMPLEX VARIABLES.

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE