Updated Stress Concentration Factors for Filleted Shafts in Bending and Tension

1996 ◽  
Vol 118 (3) ◽  
pp. 321-327 ◽  
Author(s):  
S. M. Tipton ◽  
J. R. Sorem ◽  
R. D. Rolovic
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Maximum Stress ◽  
Elastic Stress ◽  
Equivalent Stress ◽  
Graphical Form ◽  
Fatigue Crack Nucleation ◽  
Wide Range ◽  
Concentration Factors ◽  
Stress Concentration Factors

Published elastic stress concentration factors are shown to underestimate stresses in the root of a shoulder filleted shaft in bending by as much as 21 percent, and in tension by as much as forty percent. For this geometry, published charts represent only approximated stress concentration factor values, based on known solutions for similar geometries. In this study, detailed finite element analyses were performed over a wide range of filleted shaft geometries to define three useful relations for bending and tension loading: (1) revised elastic stress concentration factors, (2) revised elastic von Mises equivalent stress concentration factors and (3) the maximum stress location in the fillet. Updated results are presented in the familiar graphical form and empirical relations are fit through the curves which are suitable for use in numerical design algorithms. It is demonstrated that the first two relations reveal the full multiaxial elastic state of stress and strain at the maximum stress location. Understanding the influence of geometry on the maximum stress location can be helpful for experimental strain determination or monitoring fatigue crack nucleation. The finite element results are validated against values published in the literature for several geometries and with limited experimental data.

Stress and Strength Analysis of Equal-Diameter Tees

1991 ◽  
Vol 113 (1) ◽  
pp. 55-63 ◽  
Author(s):  
J. Zhixiang ◽  
Z. Qingjiang ◽  
Z. Siding
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Elastic Stress ◽  
Stress Factors ◽  
Strength Analysis ◽  
Stress Distributions ◽  
Concentration Factors ◽  
Stress Concentration Factors

The elastic stress distribution of four models (β=Do/Di=1.07, 1.20, unreinforced and weld-reinforced) under five typical external loadings and the strength of six models (in addition to β=1.50) under internal pressure are investigated experimentally. The maximum stress factors are obtained. The influences of weld-reinforced structure on stress distribution and strength characteristics of tees are discussed. The finite-element predictions of unreinforced tees with β=1.07, 1.11, 1.15, 1.20 are carried out. The predicted stress distributions agree well with measured results. The relation between β and stress concentration factors under various loadings are obtained.

Engineering Procedure for Calculation of Elastic Stress Concentration Factors of Bearing Pad Fretting Flaws

2009 ◽  
Author(s):  
Bogdan S. Wasiluk ◽  
Douglas A. Scarth
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Crack Initiation ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Elastic Stress ◽  
Elliptical Hole ◽  
Flat Bottom ◽  
Concentration Factors ◽  
Stress Concentration Factors

Procedures to evaluate volumetric bearing pad fretting flaws for crack initiation are in the Canadian Standard N285.8 for in-service evaluation of CANDU® pressure tubes. The crack initiation evaluation procedures use equations for calculating the elastic stress concentration factors. Newly developed engineering procedure for calculation of the elastic stress concentration factor for bearing pad fretting flaws is presented. The procedure is based on adapting a theoretical equation for the elastic stress concentration factor for an elliptical hole to the geometry of a bearing pad fretting flaw, and fitting the equation to the results from elastic finite element stress analyses. Non-dimensional flaw parameters a/w, a/c and a/ρ were used to characterize the elastic stress concentration factor, where w is wall thickness of a pressure tube, a is depth, c is half axial length, and ρ is root radius of the bearing pad fretting flaw. The engineering equations for 3-D round and flat bottom bearing pad fretting flaws were examined by calculation of the elastic stress concentration factor for each case in the matrix of source finite element cases. For the round bottom bearing pad fretting flaw, the fitted equation for the elastic stress concentration factor agrees with the finite element results within ±3.7% over the valid range of flaw geometries. For the flat bottom bearing pad fretting flaw, the fitted equation agrees with the finite element results within ±4.0% over the valid range of flaw geometries. The equations for the elastic stress concentration factor have been verified over the valid range of flaw geometries to ensure accurate results with no anomalous behavior. This included comparison against results from independent finite element calculations.

Elastic-plastic finite element analysis of hollow tubes with axially loaded axisymmetric internal projections

1993 ◽  
Vol 28 (3) ◽  
pp. 187-196 ◽  
Author(s):  
S J Hardy ◽  
A R Gowhari-Anaraki
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Elastic Stress ◽  
Low Cycle Fatigue ◽  
Kinematic Hardening ◽  
Isotropic Hardening ◽  
Published Data ◽  
Elastic Plastic ◽  
Concentration Factors ◽  
Stress Concentration Factors

The finite element method is used to study the monotonic and cyclic elastic-plastic stress and strain characteristics of hollow tubes with axisymmetric internal projections subjected to monotonic and repeated axial loading. Two geometries having low and high elastic stress concentration factors are considered in this investigation, and the results are complementary to previously published data. For cyclic loading, three simple material behaviour models, e.g., elastic-perfectly-plastic, isotropic hardening, and kinematic hardening are assumed. All results have been normalized with respect to material properties so that they can be applied to all geometrically similar components from other materials which may be represented by the same material models. Finally, normalized maximum monotonic strain and steady state strain range, predicted in the present investigation and from previously published data, are plotted as a function of the nominal load for different material hardening assumptions and different elastic stress concentration factors. These plots can be used in the low cycle fatigue design of such geometrically similar components.

Analysis of stress concentration factors for stepped plates based on a crack tip stress intensity approach

1996 ◽  
Vol 31 (3) ◽  
pp. 197-204 ◽  
Author(s):  
T G F Gray ◽  
F Tournery ◽  
J Spence
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Stress Concentration ◽  
Crack Tip ◽  
Finite Width ◽  
Sharp Corner ◽  
Wide Range ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Crack Tip Stress

The analytical equations given for stress concentration factors are based on the results of finite element analysis of stepped plates subject to uniaxial tension loading. The fillet radii at the stepped transitions were varied over a wide range, leading to elastic stress concentration factors between 1.1 and 8.3 (net stress basis). The parametric equations depend on the previously described concept of a ‘notch configuration factor’. This is similar to the crack configuration factor or compliance function used to modify the basic crack tip stress intensity solutions in the case of finite width or other problems. In the present case of the stepped plate, an energy approach was used to relate the sharp corner stress field to the corresponding sharp crack field, leading to a ‘sharp corner configuration factor’. This factor was then applied to the equation for the stress concentration factor at an elliptical hole in an infinite plate, to give a simple analytical expression for the stepped plate with a radiused fillet. The basic expression was refined further to improve the quality of fit, to an accuracy of 2 per cent with respect to the finite element models.

Stress Concentration Factors for Oblique Holes in Pressurized Thick-Walled Cylinders

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Gérard C. Nihous ◽  
Christopher K. Kinoshita ◽  
Stephen M. Masutani
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Elastic Stress ◽  
Design Guidelines ◽  
Experimental Investigations ◽  
Finite Element Analyses ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Empirical Design

Elastic stress concentration factors (SCFs) for internally pressurized thick cylindrical vessels with oblique circular crossholes are reported. Results of finite-element analyses for two wall ratios (k equal to 2.25 and 4.5) and a range of crosshole ratios (d from 0.1 to 0.5) show that SCFs sharply increase with the inclination α of the crosshole axis. These findings are consistent with earlier empirical design guidelines based on experimental investigations.

Stress Concentration Factors for Crossbores in Thick Walled Cylinders and Square Blocks

2010 ◽  
Author(s):  
Katsumi Watanabe ◽  
Susumu Terada
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Boundary Conditions ◽  
Finite Element Analyses ◽  
Wide Range ◽  
Section Viii ◽  
Concentration Factors ◽  
Stress Concentration Factors

In this study, finite element analyses were performed to investigate the stress concentration factors around cross-bores in thick walled cylinders and square blocks. As for the results, the stress concentration factors are presented relating the wide range of ratios of the diameters of main and sub bores (DH/DI) to some specific values of the wall ratios (Y). The effects of boundary conditions were also investigated. As these obtained stress concentration factors seems to show some differences from these in Appendix J of ASME Section VIII Div.3 [1], the revisions of these stress concentration factors in Div.3 are proposed.

Theoretical stress concentration factors for short shouldered plates subjected to uniform tension

2003 ◽  
Vol 38 (2) ◽  
pp. 103-113 ◽  
Author(s):  
N Troyani ◽  
A Marín ◽  
H García ◽  
F Rodríguez ◽  
S Rodríguez ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Stress Concentration ◽  
Graphical Form ◽  
Uniform Thickness ◽  
Uniform Tension ◽  
Transition Length ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Theoretical Stress

The values of the theoretical stress concentration factors for a variety of geometries and loads are available in a number of well-known publications. It is shown in this work that the reported existing results neglect the length of the members in the direction of the applied loads, and it is also shown that shorter lengths may have very significant effects on the magnitudes of the stress concentration factors. The finite element determined in-plane theoretical stress concentration factors for uniform thickness short shouldered plates subjected to uniform tension at the wide end and held longitudinally at the narrow end, for practical ranges of the fillet radius values, are reported and are presented in the standard graphical form. For completeness, other types of boundary condition have also been examined in this work. The value of the transition length between long and short plates is reported as well.

Stress concentration factors for the torsion of curved beams of arbitrary cross-section

2006 ◽  
Vol 220 (12) ◽  
pp. 1709-1726 ◽  
Author(s):  
R E Cornwell
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Cross Section ◽  
Cross Sections ◽  
Shear Stresses ◽  
Curved Beams ◽  
Finite Element Implementation ◽  
Out Of Plane ◽  
Concentration Factors ◽  
Stress Concentration Factors

There are numerous situations in machine component design in which curved beams with cross-sections of arbitrary geometry are loaded in the plane of curvature, i.e. in flexure. However, there is little guidance in the technical literature concerning how the shear stresses resulting from out-of-plane loading of these same components are effected by the component's curvature. The current literature on out-of-plane loading of curved members relates almost exclusively to the circular and rectangular cross-sections used in springs. This article extends the range of applicability of stress concentration factors for curved beams with circular and rectangular cross-sections and greatly expands the types of cross-sections for which stress concentration factors are available. Wahl's stress concentration factor for circular cross-sections, usually assumed only valid for spring indices above 3.0, is shown to be applicable for spring indices as low as 1.2. The theory applicable to the torsion of curved beams and its finite-element implementation are outlined. Results developed using the finite-element implementation agree with previously available data for circular and rectangular cross-sections while providing stress concentration factors for a wider variety of cross-section geometries and spring indices.

The Stress Concentration Factors in Cylindrical Tubes with Transverse Circular Holes

1959 ◽  
Vol 10 (4) ◽  
pp. 326-344 ◽  
Author(s):  
H. T. Jessop ◽  
C. Snell ◽  
I. M. Allison
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
Stress System ◽  
Complete Knowledge ◽  
Geometrical Shapes ◽  
Cylindrical Tubes ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Better Than

The “frozen stress” techniques of photoelasticity can give a complete knowledge of the stress, system in a solid body, but the examination of the stresses requires more time and care than in corresponding flat plate tests. In tests on tubes with transverse circular holes, sponsored by The Royal Aeronautical Society, all practicable geometrical shapes are examined and the maximum stress is measured in tension, bending and torsion. The results are comprehensive and show the inadequacy of previous results. In all cases the maximum stress occurs inside the bore of the hole. The accuracy of all the graphs of stress concentration factors is better than five per cent.

An Estimation Formula of the Stress Concentration Factor of the Butt-Welded Joint

2007 ◽  
Vol 353-358 ◽  
pp. 1995-1998
Author(s):  
Byeong Choon Goo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Gas Metal Arc Welding ◽  
Element Analysis ◽  
Butt Weld ◽  
Estimation Formula ◽  
Metal Arc Welding ◽  
Concentration Factors ◽  
Stress Concentration Factors

The purpose of this paper is to develop an estimation formula of stress concentration factors of butt-welded components under tensile loading. To investigate the influence of weld bead profiles on stress concentration factors of double V groove butt-welded joints, butt-welded specimens were made by CO2 gas metal arc welding. And the three main parameters, the toe radius, flank angle and bead height were measured by a profile measuring equipment. By using the measured data, the influence of three parameters on the stress concentration factors was investigated by a finite element analysis. It is shown that the three parameters have similar effects on the stress concentration factors. According to the simulation results, a formula to estimate the stress concentration factors of butt-weld welded structures was proposed and the estimated concentration factors from the formula were compared with the results obtained by the finite element analysis. The two results are in a good agreement.

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