On the Stress Intensity Factors of Cracked Beams for Structural Analysis

2011 ◽  
Vol 488-489 ◽  
pp. 379-382 ◽  
Author(s):  
Erasmo Viola ◽  
Yong Li ◽  
Nicholas Fantuzzi
Keyword(s):  
Stress Intensity ◽  
Structural Analysis ◽  
Cross Section ◽  
Stress Intensity Factors ◽  
Circular Cross Section ◽  
Bending Moment ◽  
Intensity Factors ◽  
Close Approximation ◽  
Shear Forces ◽  
Cracked Beams

In this paper simple engineering methods for a fast and close approximation of stress intensity factors of cracked beams and bars, subjected to bending moment, normal and shear forces, as well as torque, are examined. As far as the circular cross section is concerned, comparisons are made on the base of numerical calculations. The agreement between the present results and those previously published is discussed. New formulae for calculating the stress intensity factors are proposed.

Mode III Stress Intensity Factors of Surface Crack in Round Bars

2011 ◽  
Vol 214 ◽  
pp. 192-196 ◽  
Author(s):  
Al Emran Ismail ◽  
Ahmad Kamal Ariffin ◽  
Shahrum Abdullah ◽  
Mariyam Jameelah Ghazali ◽  
Ruslizam Daud
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Crack Depth ◽  
Crack Tip ◽  
Bending Moment ◽  
Surface Cracks ◽  
Intensity Factors ◽  
Mode Iii ◽  
Element Analysis ◽  
Proposed Model

This study presents a numerical investigation on the stress intensity factors (SIF), K of surface cracks in round bars that were obtained under pure torsion loadings or mode III. ANSYS finite element analysis (FEA) was used to determine the SIFs along the crack front of surface cracks embedded in the solid circular bars. 20-node isoparametric singular elements were used around the crack tip by shifting the mid-side node ¼-position close to a crack tip. Different crack aspect ratio, a/b were used ranging between 0.0 to 1.2 and relative crack depth, a/D were ranged between 0.1 to 0.6. Mode I SIF, KI obtained under bending moment was used to validate the proposed model and it was assumed this proposed model validated for analyzing mode III problems. It was found that, the mode II SIF, FII and mode III SIF, FIII were dependent on the crack geometries and the sites of crack growth were also dependent on a/b and a/D.

Stress Intensity Factors for Plate Bending and Shearing Problems

1994 ◽  
Vol 61 (3) ◽  
pp. 719-722 ◽  
Author(s):  
A. T. Zehnder ◽  
Chung-Yuen Hui
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Plate Theory ◽  
Infinite Plate ◽  
Bending Moment ◽  
Far Field ◽  
Intensity Factors ◽  
Arbitrary Angle ◽  
Cracked Plate ◽  
Finite Crack

Stress intensity factors for a finite crack in an infinite plate are calculated assuming Kirchhoff plate theory. Two problems are considered: a cracked plate subjected to uniform far-field shearing, and a cracked plate subjected to uniform far-field bending moment. In both cases the crack is oriented at an arbitrary angle to the axis of loading.

Boundary-Singular Integral Equation Method to Calculate the Bending Center and Stress Intensity Factors of Cracked Cylinder under Saint-Venant Bending

2007 ◽  
Vol 348-349 ◽  
pp. 197-200
Author(s):  
Xin Yan Tang
Keyword(s):  
Integral Equation ◽  
Stress Intensity ◽  
Singular Integral Equation ◽  
Integral Equations ◽  
Cross Section ◽  
Singular Integral ◽  
Stress Intensity Factors ◽  
Singular Integral Equations ◽  
Intensity Factors ◽  
Cracked Cylinder

Using single crack solution and regular plane harmonic function, the Saint-Venant bending problem of a cracked cylinder with general cross section is formulated in terms of two sets of boundary-singular integral equations, which can be solved by using the methods for combination of boundary element and singular integral equation methods. The concept of bending center used in strength of materials is extended to this bending problem. Theoretical formulae to calculate the bending center and stress intensity factors in cracked cylinder are derived and expressed by the solutions of the integral equations. Based on these results, some numerical examples are given for different configurations of the cylinder cross section as well as the crack parameters.

Finite Element Model Development for Structural Integrity of Shafts with Circumferential and Arbitrary Oriented Cracks

2015 ◽  
Vol 813-814 ◽  
pp. 905-909 ◽  
Author(s):  
R. Pramod ◽  
M.E. Shashi Kumar ◽  
S. Mohan Kumar
Keyword(s):  
Finite Element ◽  
Cylindrical Shell ◽  
Stress Intensity ◽  
Finite Element Model ◽  
Stress Intensity Factors ◽  
Structural Integrity ◽  
Accurate Determination ◽  
Bending Moment ◽  
Element Model ◽  
Intensity Factors

Tubular drive shafts are subjected to combined axial tension, torsional moment and bending moment. The structural integrity of the driveshaft is investigated by evaluating the change in strength, stiffness and the life of the driveshaft with the change in the crack length. A review of driveshaft failure analysis case histories identifies circumferential crack and arbitrarily oriented cracks to be critical. The singular stress field around a crack tip in a general shell structure is characterized by mixed mode membrane and bending stress intensity factors. Accurate determination of these stress intensity factors (less than 1%) are carried out by a subprogram named as 3MBSIF. The validation of Finite element model using ABAQUS and post processing subprogram 3MBSIF together is carried out using benchmarks, a set of standard test problems with known target solutions. Further SIFs are derived for cylindrical shell and the driveshaft under the action of bending moment. To quantify the change in the compliance of cylindrical shell and the driveshaft with change in crack lengths is studied by performing Modal Analysis. It was observed that the variation in frequency is higher for smaller crack angles.

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