Accession Number:

ADA374131

Title:

Crack Propagation Theories

Descriptive Note:

Corporate Author:

LEHIGH UNIV BETHLEHEM PA

Personal Author(s):

Report Date:

1967-10-01

Pagination or Media Count:

172.0

Abstract:

This article consists of two parts. In the first part, the crack propagation theories for brittle and quasi-brittle solids fracturing under a single application of the external loads are considered. The emphasis has been on the dynamic aspects of the fracture phenomenon and the related quantitative theories. Thus, the problem is discussed only from the viewpoint of continuum mechanics and classical thermodynamics. Two theoretical approaches are presented in detail. These are the dynamic crack propagation theory based on the concept of modulus of cohesion proposed by Barenblatt and various forms of the energy balance theory based essentially on the ideas proposed by Griffith. A detailed analysis of the energy balance around the periphery of the crack is given and it is shown that the energy available at the crack periphery to create new fracture surfaces is equivalent to the crack closure energy, which is different from the released strain energy if the inertia effects are not negligible. The results are applied to plane extensional and anti-plane shear problems. The techniques used in and the results obtained from the available experimental studies are then discussed.

Subject Categories:

  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE