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.

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.

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.

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.

Stresses in torispherical drumheads: A critical evaluation

1966 ◽  
Vol 1 (2) ◽  
pp. 89-101 ◽  
Author(s):  
H Fessler ◽  
P Stanley
Keyword(s):  
Stress Concentration ◽  
Empirical Equation ◽  
Elastic Stress ◽  
Critical Evaluation ◽  
Stress Distributions ◽  
Head Shape ◽  
Codes Of Practice ◽  
Analytical Work ◽  
Concentration Factors ◽  
Stress Concentration Factors

An empirical equation is used to compare the results of the authors' extensive photoelastic study with stress concentration factors and other forms of head shape factor obtained from independent experimental and analytical work and from some codes of practice. Important differences are shown between the stress distributions in a number of shallow, thin models and a prototype and some analytical solutions. The variations of elastic stress concentration factor with wall thickness and with knuckle radius obtained from the photoelastic work are compared with other versions. The simplifications implicit in the recommendations of codes of practice are outlined and some recommendations are made for further work.

The Stress Distribution in a Strip Loaded in Tension by Means of a Central Pin

1956 ◽  
Vol 23 (1) ◽  
pp. 85-90
Author(s):  
P. S. Theocaris
Keyword(s):  
Exact Solution ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Approximation Method ◽  
Infinite Length ◽  
Stress Distributions ◽  
Axial Hole ◽  
Optimum Diameter ◽  
Concentration Factors ◽  
Stress Concentration Factors

Abstract It is the purpose of this paper to give an exact solution for the stress distribution resulting from loading a perforated strip in tension through a rigid pin filling the hole. The strip is regarded as of an infinite length and having a single axial hole. Stress distributions are found by an alternating approximation method and the stresses are tabulated in the form of stress-concentration factors for different values of diameter of the hole. The influence of size of the hole on the stress concentration in the strip is investigated and the optimum diameter of the hole is evaluated.

Elastic stress concentration factors in finite plates under tensile loads

1966 ◽  
Vol 1 (4) ◽  
pp. 306-312 ◽  
Author(s):  
S M Ibrahim ◽  
H McCallion
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Numerical Solutions ◽  
Elastic Stress ◽  
Governing Equations ◽  
Uniaxial Load ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors

New results for stress concentration factors at notches, fillets and circular holes in plates under uniaxial load are presented. These stress concentration factors have been obtained from numerical solutions of the governing equations for elastic stress distribution and are compared with experimental and theoretical factors published by other workers. The generality of the method used is indicated in the solutions obtained for finite plates with a number of holes and for a plate with a hole and notches.

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.

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