Stress Intensity Factors for a Crack Emanating Non-Radially From a Circular Hole Under Arbitrary Loading

2006 ◽  
Author(s):  
Simon C. F. Sheng
Keyword(s):  
Stress Intensity ◽  
Circular Hole ◽  
Stress Intensity Factors ◽  
Structural Integrity ◽  
Plane Deformation ◽  
Elastic Solid ◽  
Dislocation Model ◽  
Mode Ii ◽  
Intensity Factors ◽  
Mode Iii

Stress intensity factors are found for a crack emanating from a circular hole in an elastic solid which is in a state of plane deformation resulting from loads applied at infinity or pressure applied internally at the faces of the crack and the hole. The results, including Mode-I (opening) and Mode-II (shearing) stress intensity factors, are obtained numerically by means of a dislocation model which conveniently allows for general loading and, consequently, can easily handle the case where a crack emanates non-radially from a hole. Good agreement is found with published values for the special case when the crack is radial and the loading consists of remote tension and uniform pressure at the surface of the hole. Also included in the present paper are results for the case when both the hole and the crack are pressurized. Although the subject elastic solid is an infinite medium, the results of this paper serve as good estimates when the hole is relatively small in a finite component and is distant from the component edge. Since in most circumstances a real crack does not orient itself radially from a hole, this paper provides analysts information to decide whether Mode-II fracture needs to be considered in assessing the structural integrity of a component with a hole. Similarly, when the problem is 3-dimensional, the results of this paper imply that Mode-III (tearing) fracture may also need to be considered.

Mode II and mode III stress singularities and intensities at a crack tip terminating on a transversely isotropic-orthotropic bimaterial interface

1994 ◽  
Vol 444 (1922) ◽  
pp. 447-460 ◽  
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Crack Tip ◽  
Transversely Isotropic ◽  
Bimaterial Interface ◽  
Mode Ii ◽  
Stress Singularities ◽  
Intensity Factors ◽  
Mode Iii ◽  
Orthotropic Media

In a recent paper (referred to as I) we obtained inter alia , the stress and displacement fields at the tips of a transverse crack in an isotropic medium sandwiched between orthotropic media under in-plane loading (mode II). The crack was lying wholly within the isotropic medium so that the singularity at the crack tip was of the usual inverse square root type. In this paper, the analysis is extended to the case when the tip of the crack terminates on the transversely isotropic-orthotropic bimaterial interface and the nature of the singularity at the crack tip depends on the elastic properties of both media. The analysis is performed for both inplane (mode II) and out-of-plane (mode III) shear loading. General solutions are obtained for the crack tip stress singularities and corresponding stress intensity factors, together with the influence of the elastic properties and geometry of the media upon the stress field. These solutions are specialized to the limiting case when the crack terminates on the interface between dissimilar isotropic media in order to demonstrate consistency with published results. As in I, the solutions are used to investigate the influence of ply angle θ upon the stress singularities in [± θ /90°] s fibre-reinforced composite laminates. For this analysis, the outer angle-ply sublaminates are treated macroscopically as homogeneous orthotropic media whose elastic constants are obtained using the classical lamination approximation. Calculations are also carried out to study the variation of stress intensity factors with the ply angle and outer sublaminate thickness.

Three-Dimensional Mode Separation to Obtain Stress Intensity Factors

2006 ◽  
Author(s):  
Pei Gu ◽  
R. J. Asaro
Keyword(s):  
Stress Intensity ◽  
Crack Propagation ◽  
Stress Intensity Factors ◽  
Three Dimensional ◽  
Integral Approach ◽  
Mode I ◽  
Mode Ii ◽  
Intensity Factors ◽  
Mode Iii ◽  
Mode Separation

For mixed-mode loading at a crack tip under small-scale yielding condition, mode I, mode II and mode III stress intensity factors control the crack propagation. This paper discusses three-dimensional mode separation to obtain the three stress intensity factors using the interaction integral approach. The 2D interaction integral approach to obtain mode I and mode II stress intensity factors is derived to 3D arbitrary crack configuration for mode I, mode II and mode III stress intensity factors. The method is implemented in a finite element code using domain integral method and numerical examples show good convergence for the domains around the crack tip. A complete solution for the three stress intensity factors is obtained for a bar with inclined crack face to the cross-section from numerical calculations. The solution for the bar is plotted into curves in terms of a set of non-dimensional parameters for practical engineering purpose. From the solution, mode mixity along the crack front and its implication to the direction of crack propagation is discussed.

scholarly journals Dynamic Mixed Mode I-II Crack Kinking Under Oblique Stress Wave Loading in Brittle Solids

1990 ◽  
Vol 57 (1) ◽  
pp. 117-127 ◽  
Author(s):  
Chien-Ching Ma
Keyword(s):  
Stress Intensity ◽  
Stress Wave ◽  
Stress Intensity Factors ◽  
Crack Tip ◽  
Elastic Solid ◽  
Perturbation Parameter ◽  
Intensity Factors ◽  
Linear Superposition ◽  
Dynamic Stress Intensity Factors ◽  
Brittle Solids

The dynamic stress intensity factors of an initially stationary semi-infinite crack in an unbounded linear elastic solid which kinks at some time tf after the arrival of a stress wave is obtained as a function of kinking crack tip velocity v, kinking angle δ, incident stress wave angle α, time t, and the delay time tf. A perturbation method, using the kinking angle δ as the perturbation parameter, is used. The method relies on solving simple problems which can be used with linear superposition to solve the problem of a kinked crack. The solutions can be compared with numerical results and other approximate results for the case of tf = 0 and give excellent agreement for a large range of kinking angles. The elastodynamic stress intensity factors of the kinking crack tip are used to compute the corresponding fluxes of energy into the propagating crack-tip, and these results are discussed in terms of an assumed fracture criterion.

Crack Propagation in Rolling Line Contacts

1992 ◽  
Vol 114 (4) ◽  
pp. 690-697 ◽  
Author(s):  
H. Salehizadeh ◽  
N. Saka
Keyword(s):  
Stress Intensity ◽  
Crack Propagation ◽  
Stress Intensity Factors ◽  
Mode Ii ◽  
Pure Mode ◽  
Intensity Factors ◽  
Crack Face ◽  
Normal Loading ◽  
Line Contacts ◽  
Crack Growth Model

The stress intensity factors for short straight and branched subsurface cracks subjected to a Hertzian loading are calculated by the finite element method. The effect of crack face friction on stress intensity factors is considered for both straight and branched cracks. The calculations show that the straight crack is subjected to pure mode II loading, whereas the branched crack is subjected to both mode I and mode II, with ΔKI/ΔKII < 0.25. Although KI is small, it strongly influences KII by keeping the branched crack faces apart. Based on the ΔKII values and Paris’s crack growth model, the number of stress reversals required to grow a crack in a rolling component from an initial threshold length to the final spalling length was estimated. It was found that the crack propagation period is small compared with the expected bearing fatigue life. Therefore, crack propagation is not the rate controlling factor in the fatigue failure of bearings operating under normal loading levels.

The Effect of Transverse Shear in a Cracked Plate Under Skew-Symmetric Loading

1979 ◽  
Vol 46 (3) ◽  
pp. 618-624 ◽  
Author(s):  
F. Delate ◽  
F. Erdogan
Keyword(s):  
Stress Intensity ◽  
Transverse Shear ◽  
Stress Intensity Factors ◽  
Orthotropic Materials ◽  
Shear Load ◽  
Intensity Factors ◽  
Mode Iii ◽  
Shear Loads ◽  
Elasticity Solutions ◽  
Symmetric Loading

The problem of an elastic plate containing a through crack and subjected to twisting moments or transverse shear loads is considered. By using a bending theory which allows the satisfaction of the boundary conditions on the crack surface regarding the normal and the twisting moments and the transverse shear load separately, it is found that the resulting asymptotic stress field around the crack tip becomes identical to that given by the elasticity solutions of the plane strain and antiplane shear problems. The problem is solved for uniformly distributed or concentrated twisting moment or transverse shear load and the normalized Mode II and Mode III stress-intensity factors are tabulated. The results also include the effect of the Poisson’s ratio and material orthotropy for specially orthotropic materials on the stress-intensity factors.

Estimation of Mixed-Mode Stress Intensity Factors with Presence of the Confinement Parameters T-Stress and A3

2016 ◽  
Vol 18 ◽  
pp. 52-57
Author(s):  
Lahouari Fodil ◽  
Abdallah El Azzizi ◽  
Mohammed Hadj Meliani
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Mixed Mode ◽  
Compact Tension ◽  
Mode I ◽  
Mode Ii ◽  
Mixed Mode Fracture ◽  
Intensity Factors ◽  
Element Analysis ◽  
T Stress

A failure criterion is proposed for ductile fracture in U-notched components under mixed mode static loading. The Compact Tension Shear (CTS) is the preferred test specimen used to determine stress intensity factor in the mode I, mode II and the mixed-mode fracture. In this work, the mode I and mode II stress intensity factors were computed for different notch ratio lengths 0.1<a/W<0.7, of the inner radius of notch 0.25mm<ρ<4mm and load orientation angles 0°<α< 90° using finite element analysis. However, a review of numerical analysis results reveals that the conventional fracture criteria with only stress intensity factors (NSIFs) Kρ first term of Williams’s solution provide different description of stress field around notch zone comparing with results introduce the second and third parameter T-stress and A3.

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