Journal ArticleDOI
The structure of the near-tip field during transient elastodynamic crack growth
L. B. Freund,Ares J. Rosakis +1 more
TLDR
In this article, the authors considered the influence of the transient nature of the crack growth process on the stress field in the immediate vicinity of a crack tip during nonsteady growth.Abstract:
T he process of dynamic crack growth in a nominally elastic malerial under conditions of plane strain or plane stress is considered. Of particular concern is the influence of the transient nature of the process on the stress field in the immediate vicinity of the crack tip during nonsteady growth. Asymptotically, the crack tip stress field is square root singular at the crack tip, with the angular variation of the singular field depending weakly on the instantaneous crack tip speed and with the instantaneous stress intensity factor being a scalar multiplier of the singular field. However, for a material particle at a small distance from the moving crack, the local stress field depends not only on instantaneous values of crack speed and stress intensity factor, but also on the past history of these lime-dependent quantities. A representation of the crack tip field is obtained in the form of an expansion about the crack up in powers of radial coordinate, with the coefficients depending on the time rates of change of crack tip speed and stress intensity factor. This representation is used to interpret some experimental observations, with the conclusion that the higher-order expansion provides an accurate description of crack tip fields under fairly severe transient conditions. In addition, some estimates are made of the practical limits of using a stress intensity factor field alone to characterize the local fields.read more
Citations
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Journal ArticleDOI
Three Dimensional Cohesive-Element Analysis and Experiments of Dynamic Fracture in C300 Steel
TL;DR: In this article, coherent gradient sensing (CGS) has been used to study dynamic fracture in C300 maraging steel, where the specimens were subjected to three-point bend impact loading under a drop weight tower and high speed photographs of the CGS interferograms were analyzed to determine the crack tip location, the velocity and the dynamic fracture toughness as a function of time.
Journal ArticleDOI
Crack-tip stress fields for dynamic fracture in functionally gradient materials
TL;DR: In this article, an asymptotic expansion of the stress field around a crack propagating at constant velocity in a Functionally Gradient Material (FGM) is developed, and the analysis reveals that the crack-tip stress fields retain the inverse square root singularity and only the higher order terms in the expansion are influenced by the material nonhomogeneity.
Journal ArticleDOI
Highly transient elastodynamic crack growth in a bimaterial interface : higher order asymptotic analysis and optical experiments
TL;DR: In this article, a higher order asymptotic analysis of the transient deformation field surrounding the tip of a crack running dynamically along a bimaterial interface is presented, which furnishes displacement potentials which are used to evaluate explicitly the near-tip transient stress field.
Journal ArticleDOI
Computational dynamic fracture mechanics
TL;DR: A review on the state of the art in computational dynamic fracture mechanics can be found in this article, where a special attention is focused on the asymptotic eigen fields for various states of dynamic crack tips.
Journal ArticleDOI
Dynamic fracture-path prediction in impact fracture phenomena using moving finite element method based on Delaunay automatic mesh generation
TL;DR: In this paper, a mixed-phase simulation with fracture-path prediction mode using a postulated propagation-direction criterion together with experimentally obtained crack propagation history is presented, which uses an automatic moving finite element method that incorporates the Delaunay automatic triangulation.
References
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Dynamic Fracture Mechanics
TL;DR: In this article, basic elastodynamic solutions for a stationary crack and asymptotic fields near a moving crack tip are presented. But they do not consider the elasticity and rate effects during crack growth.
Book
Dynamic Fracture Mechanics
L. B. Freund,John W. Hutchinson +1 more
TL;DR: In this article, basic elastodynamic solutions for a stationary crack and asymptotic fields near a moving crack tip are presented. But they do not consider the elasticity and rate effects during crack growth.
Journal ArticleDOI
An experimental investigation into dynamic fracture: I. Crack initiation and arrest
TL;DR: In this paper, the authors examined crack initiation and arrest in thin sheets of Homalite-100 and showed that cracks can propagate rapidly with constant velocity even though the stress intensity factor varies considerably during this propagation.
Journal ArticleDOI
On crack-tip stress state: An experimental evaluation of three-dimensional effects
TL;DR: In this article, the authors investigated the extent of the crack-tip stress field using reflected and transmitted caustics and found that plane-stress conditions prevail at distances from the crack tip greater than half the specimen thickness, while no significant plane-strain region is detected.
Journal ArticleDOI
The determination of dynamic fracture toughness of AISI 4340 steel by the shadow spot method
TL;DR: In this article, the dynamic crack propagation experiments have been performed using wedge loaded double cantilever beam specimens of an austenitized, quenched and tempered 4340 steel.