
Accession Number : ADP000010
Title : A Nonlinear Fracture Mechanics Predictive Procedure for the Short Crack Effect in Fatigue,
Corporate Author : BATTELLE COLUMBUS LABS OH
Personal Author(s) : Ahmad,J. ; Hopper,A. T. ; Kanninen,M. F. ; Leis,B. N. ; Papaspyropoulos,V.
Report Date : SEP 1982
Pagination or Media Count : 26
Abstract : When the predictive techniques of linear elastic fracture mechanics (LEFM) are applied to physically short fatigue cracks, it is often found that the actual crack growth rate is considerably underestimated. This means that damage tolerance and other fracture control methods that rely on accurate crack growth predictions could be quite nonconservative. Consequently, considerable attention has been devoted to identifying the causes of the accelerated growth rates and on ways of improving upon the currently available predictions. Virtually all of these have been based exclusively upon LEFM considerations. In contrast, this paper addresses the short crack problem from the point of view that an elasticplastic fracture mechanics parameter may offer the basis for a resolution of the dilemma. The specific approach that is taken is one that focusses on the cracktip crackopening displacement (CTOD) as a characterizing parameter. The use of CTOD is at least as general as current LEFM procedures. Of equal importance, the CTOD may possibly be valid where LEFM is not. An illustrative example is used to show the nonlinear character of this approach.
Descriptors : *Finite element analysis, *Metals, *Cracks, *Crack propagation, *Fatigue(Mechanics), Mathematical prediction, Numerical methods and procedures, Elastic properties, Plastic properties, Yield strength, Modulus of elasticity, Strain hardening, Equations, J integrals, Nonlinear analysis, Displacement, Algorithms, Experimental data, Aluminum alloys, Steel
Subject Categories : Metallurgy and Metallography
Theoretical Mathematics
Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE