Stress-Intensity Factor for a Three-Dimensional Rectangular Crack

1981 ◽  
Vol 48 (2) ◽  
pp. 309-312 ◽  
Author(s):  
M. K. Kassir
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Plane Strain ◽  
Integral Transform ◽  
Three Dimensional ◽  
Elastic Solid ◽  
Normal Loading ◽  
Rectangular Crack ◽  
Strain Stress

An integral transform solution is developed to reduce the problem of determining the stress-intensity factor of a narrow three-dimensional rectangular crack to the solution of a Fredholm integral equation of the second kind. The crack is assumed to be embedded in an infinite elastic solid subjected to normal loading. Numerical results are presented to indicate a reduction in the value of the stress-intensity factor from the plane strain case. For an elongated rectangular crack the plane-strain stress-intensity factor is recovered.

ELASTODYNAMIC STRESS INTENSITY FACTOR FOR A FINITE CRACK IN ELASTIC SOLID UNDER 3D TRANSIENT LOADING OF MODE I

2013 ◽  
Vol 05 (04) ◽  
pp. 1350044
Author(s):  
XIANHONG MENG ◽  
ZHAOYU BAI ◽  
MING LI
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Integral Transform ◽  
Elastic Solid ◽  
Scattered Wave ◽  
Mode I ◽  
Finite Width ◽  
Infinite Length ◽  
Distance Ratio

In this paper, the three-dimensional dynamic problem for an infinite elastic medium weakened by a crack of infinite length and finite width is analyzed, while the crack surfaces are subjected to mode I transient linear tractions. The integral transform approach is applied to reduce the governing differential equations to a pair of coupled singular integral equations, whose solutions can be obtained with the typical iteration method. The analytical solution of the stress intensity factor when the first wave and the first scattered wave reach the investigated crack tip is obtained. Numerical results are presented for different values of the width-to-longitudinal distance ratio z/l. It is found that the stress intensity factor decreases with the arrival of the first scattered longitudinal wave and increases with the arrival of the first scattered Rayleigh wave and tends to be stable. The static value considering both the first scattered wave and the first wave is about 50% greater than that considering only the first wave, and then the effect of the reflected wave is remarkable and deserves further study.

Three-Dimensional Stress Field Near the Crack Front of a Thin Elastic Plate

1988 ◽  
Vol 55 (4) ◽  
pp. 805-813 ◽  
Author(s):  
T. Nakamura ◽  
D. M. Parks
Keyword(s):  
Stress Intensity Factor ◽  
Free Surface ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Plane Strain ◽  
Crack Front ◽  
Three Dimensional ◽  
Radial Distance ◽  
Corner Singularity ◽  
Two Dimensional

Based on very detailed full-field finite element analysis of the near tip region of a thin isotropic elastic plate, the three-dimensional stress state in the vicinity of a through-crack front is characterized. The computed stress field reveals strong three-dimensional effects within a radial distance of about one-half thickness from the crack-tip. Further away from the tip, through-thickess variation of field quantities decreases and, at the radial distance of approximately 1.5 times the thickness, in-plane stresses merge with the dominant two-dimensional plane stress solutions. These “two-dimensional-three-dimensional” transition distances are essentially independent of the material Poisson’s ratio, yet the amplitude of variation is greatly affected by its value. The influence of Poisson’s ratio is clearly illustrated by local J along the crack front, which shows much higher variation through the thickness for nearly incompressible solids. At points very close to the crack front, relative magnitudes of out-of-plane strain components become very small, and asymptotic plane strain conditions prevail locally. On the mid-plane of the plate, the crack tip field converges to that given by the local plane strain stress intensity factor solution within a radial distance from the tip of less than 0.5 percent of thickness. In addition, it is found that the field near the intersection of crack front and free surface may be characterized by the corner singularity of a quarter infinite crack in a half space. The size of this domain is inferred from the gradient of local stress intensity factor with respect to distance from the free surface, and it appears that the corner singularity region extends up to a spherical radius of about 3 percent of plate thickness away from the intersection. Also the amplitude of the corner singularity field is described by a corner stress intensity factor, and its magnitude is determined for thin plates of various Poisson’s ratios.

Analysis of the Three-Dimensional Zone around the Interfacial Crack Tip: The K-Influence Domain Range in the Plane Stress State

2017 ◽  
Vol 754 ◽  
pp. 119-122
Author(s):  
Jelena M. Djoković ◽  
Snežana D. Vulović ◽  
Ružica R. Nikolić ◽  
Miroslav M. Živković ◽  
Branislav Hadzima
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Stress State ◽  
Intensity Factor ◽  
Plane Strain ◽  
Plane Stress ◽  
Three Dimensional ◽  
Crack Tip ◽  
Plane Stress State ◽  
Relevant Parameter

The bimaterial sample was analyzed to determine the three-dimensional zone at the interface crack tip and the field in the plane stress state. The solutions for the complete 3D field in different zones around the crack tip were approximated by the plane stress and plane strain states' asymptotic solutions. The difference between the solutions for the plane stress and plane strain states is defined by the three variables. The established relationship between the far field and the field around the crack tip in the plane strain conditions, enables relating the measured experimental results of the stress intensity factor to results for the stress intensity factor for the field around the crack tip, which represent the more relevant parameter for formulating the fracture criterion.

Stress Intensity Factors for Penny-Shaped Cracks: Part 1—Infinite Solid

1967 ◽  
Vol 34 (4) ◽  
pp. 947-952 ◽  
Author(s):  
F. W. Smith ◽  
A. S. Kobayashi ◽  
A. F. Emery
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Elastic Solid ◽  
Pure Bending ◽  
Normal Loading ◽  
Penny Shaped Crack ◽  
Shaped Crack ◽  
Symmetric Loading ◽  
Embedded Crack

An expression is developed for the stress intensity factor of a penny-shaped crack in an infinite elastic solid subjected to nonaxisymmetric normal loading. The stress intensity factor can then be determined for penny-shaped cracks in infinite or finite solids subjected to symmetric loading about the plane containing the crack. The singular state associated with the embedded crack with finite, nonaxisymmetric normal loading is that of plane strain. Results are also presented for two problems: A penny-shaped crack subjected to two symmetrically located concentrated forces and a penny-shaped crack in a large beam subjected to pure bending.

Stress Intensity Factor for Repaired Circumferential Cracks in Pipe With Bonded Composite Wrap

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
F. Benyahia ◽  
A. Albedah ◽  
B. Bachir Bouiadjra
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Criterion ◽  
Three Dimensional ◽  
Element Analysis ◽  
Composite Systems ◽  
Bonded Composite ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The use of composite systems as a repair methodology in the pipeline industry has grown in recent years. In this study, the analysis of the behavior of circumferential through cracks in repaired pipe with bonded composite wrap subjected to internal pressure is performed using three-dimensional finite element analysis. The fracture criterion used in the analysis is the stress intensity factor (SIF). The obtained results show that the bonded composite repair reduces significantly the stress intensity factor at the tip of repaired cracks in the steel pipe, which can improve the residual lifespan of the pipe.

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