Elliptical Crack in a Finite-Thickness Plate Subjected to Tensile and Bending Loading

1974 ◽  
Vol 96 (1) ◽  
pp. 47-54 ◽  
Author(s):  
R. C. Shah ◽  
A. S. Kobayashi
Keyword(s):  
Free Surface ◽  
Stress Intensity ◽  
Finite Thickness ◽  
Elliptical Crack ◽  
Aspect Ratios ◽  
Analytical Results ◽  
Magnification Factors ◽  
Bending Loading ◽  
Resultant Stress

Stress intensity magnification factors for an elliptical crack embedded in a finite thickness plate subjected to tensile and bending loading are estimated by judicious use of analytical results obtained previously. These analytical results involve the stress intensity magnification factors for an embedded elliptical crack approaching the free surface of a semi-infinite solid and pressurized by a constant or by a linearly varying pressure. The resultant stress intensity magnification factors for the elliptical crack in a plate are presented in graphical forms for various crack aspect ratios, eccentricity, and proximity factors.

scholarly journals Influence Coefficients to Calculate Stress Intensity Factors for an Elliptical Crack in a Plate

2002 ◽  
Author(s):  
Patrick Le Delliou ◽  
Bruno Barthelet
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Atomic Energy Commission ◽  
Finite Thickness ◽  
Elliptical Crack ◽  
Intensity Factors ◽  
Normal Loading ◽  
Influence Coefficients ◽  
Wide Range

Crack assessment in engineering structures relies first on accurate evaluation of the stress intensity factors. In recent years, a large work has been conducted in France by the Atomic Energy Commission to develop influence coefficients for surface cracks in pipes. However, the problem of embedded cracks in plates (and pipes) which is also of practical importance has not received so much attention. Presently, solutions for elliptical cracks are available either in infinite solid with a polynomial distribution of normal loading or in plate, but restricted to constant or linearly varying tension. This paper presents the work conducted at EDF R&D to obtain influence coefficients for plates containing an elliptical crack with a wide range of the parameters: relative size (2a/t ratio), shape (a/c ratio) and crack eccentricity (2e/t ratio where e is the distance from the center of the ellipse to the plate mid plane). These coefficients were developed through extensive 3D finite element calculations: 200 geometrical configurations were modeled, each containing from 18000 to 26000 nodes. The limiting case of the tunnel crack (a/c = 0) was also analyzed with 2D finite element calculation (50 geometrical configurations). The accuracy of the results was checked by comparison with analytical solutions for infinite solids and, when possible, with solutions for finite-thickness plates (generally loaded in constant tension). These solutions will be introduced in the RSE-M Code that provides rules and requirements for in-service inspection of French PWR components.

Stress Intensity Factor Solutions for Subsurface Flaws in Plates Subjected to Polynomial Stress Distributions

2016 ◽  
Author(s):  
Kai Lu ◽  
Jinya Katsuyama ◽  
Yinsheng Li ◽  
Fuminori Iwamatsu
Keyword(s):  
Stress Intensity Factor ◽  
Free Surface ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Stress Distributions ◽  
Thickness Direction ◽  
Finite Element Analyses ◽  
Aspect Ratios ◽  
Order Polynomial ◽  
Fourth Order Polynomial

Stress intensity factor (SIF) solutions for subsurface flaws near the free surface in plates were numerically investigated based on the finite element analyses. The flaws with aspect ratios a/ℓ = 0, 0.1, 0.2, 0.3, 0.4 and 0.5, the normalized ratios a/d = 0, 0.1, 0.2, 0.4, 0.6 and 0.8 and d/t = 0.01 and 0.1 were taken into account, where a is the half flaw depth, ℓ is the flaw length, d is the distance from the center of the subsurface flaw to the nearest free surface and t is the wall thickness. Fourth-order polynomial stress distributions in the thickness direction were considered. Based on the results, it can be concluded that the numerical SIF solutions obtained in this study are useful in engineering applications.

Inner and Outer Cracks in Internally Pressurized Cylinders

1977 ◽  
Vol 99 (1) ◽  
pp. 83-89 ◽  
Author(s):  
A. S. Kobayashi ◽  
N. Polvanich ◽  
A. F. Emery ◽  
W. J. Love
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Finite Thickness ◽  
Internal Surface ◽  
Surface Cracks ◽  
Single Edge ◽  
Intensity Factors ◽  
Curvature Effects ◽  
Aspect Ratios ◽  
Dimensional Finite Element

Stress intensity factors of pressurized surface cracks at the internal surface and un-pressurized surface cracks at the external surface of an internally pressurized cylinder are estimated from stress intensity factors of a semi-elliptical crack in a finite-thickness flat plate. Curvature effects of the cylinder are determined by comparing two-dimensional finite element solutions of fixed-grip, single edge-notched plates and single edge-notched cylinders. Stress intensity factors for semi-elliptical cracks with crack aspect ratios of b/a = 0.2 and 0.98 at crack depths up to 80 percent of the cylindrical wall thickness are shown for internally pressurized cylinders with outer to inner diameter ratios, Ro/Ri, ranging from 10:9 to 5:4 for outer surface cracks and to 3:2 for inner surface cracks.

Embedded Elliptical Crack at a Corner

1978 ◽  
Vol 100 (1) ◽  
pp. 28-33
Author(s):  
A. S. Kobayashi ◽  
A. F. Emery ◽  
W. J. Love ◽  
A. Antipas
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Stress Concentration ◽  
High Stress ◽  
Elliptical Crack ◽  
Stress Distributions ◽  
High Stress Concentration ◽  
Magnification Factors ◽  
Elliptical Cracks ◽  
Circular Cracks

A procedure for estimating the stress intensity factor of an embedded elliptical crack near the corner in a region of high stress concentration such as pressurized or thermally shocked nozzle-to-cylinder junction is discussed. The procedure is then used to analyze two hypothetical embedded circular cracks near the corner of a nozzle-to-cylinder junction where stress distributions in the uncracked junction are known. Also shown are two new stress intensity magnification factors for two embedded elliptical cracks, i.e., b/a = 0.2 and 0.982, close to a free corner, i.e., a/h = b/h = 0.9.

scholarly journals Stress Intensity Factors for Embedded, Surface, and Corner Cracks in Finite-Thickness Plates Subjected to Tensile Loading

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2807
Author(s):  
Jesús Toribio ◽  
Beatriz González ◽  
Juan-Carlos Matos ◽  
Óscar Mulas
Keyword(s):  
Stress Intensity ◽  
Crack Depth ◽  
Finite Thickness ◽  
Tensile Load ◽  
Corner Crack ◽  
Plate Length ◽  
Aspect Ratios ◽  
Favorable Configuration ◽  
Corner Cracks ◽  
Embedded Crack

The aim of this study is to obtain the stress intensity factor (SIF) along the crack front of elliptical cracks located in finite-thickness plates subjected to imposed displacement or applied tensile load, for different crack geometries (relative depths and aspect ratios) and crack configurations (embedded, surface, and corner). The SIF was calculated from the J-integral, obtained by the finite element method. The results show how the SIF grows with the increase in the relative crack depth and with the decrease in the aspect ratio, with the corner crack being the most dangerous configuration and the embedded crack the most favorable configuration. By increasing the plate length, the SIF rises when the plate is under imposed displacement and decreases when the plate is subjected to applied tensile load, both cases tending towards the same SIF curve.

scholarly journals Interaction between line cracks in an orthotropic layer

2002 ◽  
Vol 29 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Subir Das
Keyword(s):  
Fourier Transform ◽  
Stress Intensity ◽  
Finite Thickness ◽  
Intensity Factors ◽  
Orthotropic Layer ◽  
Finite Hilbert Transform ◽  
Crack Tips ◽  
The Fourier Transform ◽  
Analytical Expressions ◽  
Elastostatic Problem

We deal with the interaction between three coplanar Griffith cracks located symmetrically in the mid plane of an orthotropic layer of finite thickness2h. The Fourier transform technique is used to reduce the elastostatic problem to the solution of a set of integral equations which have been solved by using the finite Hilbert transform technique and Cooke's result. The analytical expressions for the stress intensity factors at the crack tips are obtained for largeh. Numerical values of the interaction effect have been computed for and results show that interaction effects are either shielding or amplification depending on the location of each crack with respect to each other and crack tip spacing as well as the thickness of the layer.

Fracture of Defects Approaching a Free Surface

1975 ◽  
Vol 97 (4) ◽  
pp. 270-277 ◽  
Author(s):  
W. G. Gibbons ◽  
W. R. Andrews ◽  
G. A. Clarke
Keyword(s):  
Fracture Toughness ◽  
Fatigue Crack ◽  
Free Surface ◽  
Stress Intensity ◽  
Surface Stress ◽  
Empirical Equation ◽  
Near Surface ◽  
Fracture Characteristics ◽  
Testing Program ◽  
Measured Strain

A testing program has been run using off-centered-cracked (OCC) plate specimens to demonstrate the fracture characteristics of tunnel defects in specimens with various ligament lengths between the near surface crack tip and a free surface. Measured strain values and the fracture results compared favorably with theory up to the limits of the analyses. An empirical equation which calculates the near surface stress intensity provides extended calculational capabilities. In addition, fatigue crack growth and fracture velocities plus fracture toughness were measured for a Cr-Mo-V steel.

Sign in / Sign up

Export Citation Format

Share Document