Quasi-Static Steady Crack Growth in Small-Scale Yielding


Book Description

A numerical analysis of quasi-static, steady-state crack growth under small-scale yielding conditions has been carried out for antiplane shear (Mode III) and plane strain, Mode I. In addition to results for an elastic-perfectly plastic solid, the study includes results relating to the influence of strain hardening on stable crack growth. Limited results based on a corner theory of plasticity give some indication of the extent to which stable crack growth predictions are sensitive to the type of plasticity theory used.




Numerical Assessments of Cracks in Elastic-Plastic Materials


Book Description

In this book a systematic discussion of crack problems in elastic-plastic materials is presented. The state of the art in fracture mechanics research and assessment of cracks is documented, with the help of analytic, asymptotic methods as well as finite element computations. After a brief introduction to fracture mechanics, the two-parameter concept for stationary cracks is studied in addition to the issues in three-dimensional crack fields under coupling with strong out-of-plane effects. Cracks along interfaces and crack growth problems under mixed mode conditions are also treated. A systematic study of stress singularities for different notches is accompanied by detailed finite element computations.




Fracture Mechanics


Book Description

The proceedings of the 23rd National Symposium on Fracture Mechanics, held in College Station, Texas, June 1991, present a broad overview of the current state of the art in fracture mechanics research. Following the Swerdlow Lecture (Structural Problems in Search of Fracture Mechanics Solutions by




Comparison of Experiment and Theory for Elastic-plastic Plane Strain Crack Growth


Book Description

Recent theoretical results on elastic-plastic plane strain crack growth, and experimental results for crack growth in a 4140 steel in terms of the theoretical concepts are reviewed. The theory is based on a recent asymptotic analysis of crack surface opening and strain distributions at a quasi-statically advancing crack tip in an ideally-plastic solid. The analysis is incomplete in that some of the parameters which appear in it are known only approximately, especially at large scale yielding. Nevertheless, it suffices to derive a relation between the imposed loading and amount of crack growth, prior to general yielding, based on the assumption that a geometrically similar near-tip crack profile is maintained during growth. The resulting predictions for the variation of J with crack growth are found to fit well to the experimental results obtained on deeply cracked compact specimens.




Non-Linear Fracture


Book Description

From time to time the International Journal of Fracture has presented special matters thought to be of interest to its readers. In previous issues, for example, Dr. H.W. Liu as Guest Editor assembled a series of review papers dealing with fatigue processes and characteristics in metals and non-metals (December 1980 and April 1981). Five years ago Guest Editor W.G. Knauss collected works dealing with dynamic fracture (March and April 1985). Continuing this policy, Dr. W.G. Knauss and Dr. A.J. Rosakis of the California Institute of Technology as Guest Editors have now organized an extensive set of papers concerning the influence of non-linear effects upon the mechanics of the fracture process. This collection is based upon contributions to a relatively small international Symposium on Non Linear Fracture Mechanics held under the auspices of the International Union of Theoretical and Applied Mechanics (IUTAM) and convened at the California Institute of Technology in March 1988. It should be noted that although the description of non-linear fracture inherently encompasses a strong material science component, this aspect is not heavily emphasized in the ensuing papers due to the intentional focus upon mechanics. Volume 42 of the International Journal of Fracture will therefore, in successive issues, deal respectively with topics in (1) Damage, (2) Interfaces and Creep, (3) Time Dependence, and (4) Continuum Plasticity. On behalf of the editors and publishers, I wish to express our appreciation to Dr. Knauss, Dr. Rosakis, and their colleagues for their collective efforts.