A discussion on various estimations of elastic stress distributions and stress concentration factors for sharp edge notches

1986 ◽  
Vol 8 (4) ◽  
pp. 235-237 ◽  
Author(s):  
C SHIN
1991 ◽  
Vol 113 (1) ◽  
pp. 55-63 ◽  
Author(s):  
J. Zhixiang ◽  
Z. Qingjiang ◽  
Z. Siding

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.


1966 ◽  
Vol 1 (2) ◽  
pp. 89-101 ◽  
Author(s):  
H Fessler ◽  
P Stanley

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.


1964 ◽  
Vol 15 (1) ◽  
pp. 83-96 ◽  
Author(s):  
K. R. Rushton

SummaryThe elastic stress concentration factors for the torsion of solid and hollow shouldered shafts have been determined by means of a pure resistance electrical analogue. Fillet radii ranged from 0.05 to 1.0 times the diameter of the smaller shaft, and the shoulder diameter increased from 1.0 to 8.10 times the diameter of the smaller shaft. A comparison is made with the results of other techniques. A study has also been made of the formation of a plastic region in the neighbourhood of the fillet.


1981 ◽  
Vol 16 (4) ◽  
pp. 217-226 ◽  
Author(s):  
M A Teixeira ◽  
R D McLeish ◽  
S S Gill

Simplified charts are presented for elastic stress concentration factors due to radial loads and circumferential and longitudinal moments applied to circular branches normal to cylindrical pressure vessels. The charts are based on the procedures given in Appendix G of BS 5500. The assumptions implied in Appendix G and the limitations on the geometrical parameters ro/r and r/t are discussed. A modification to Appendix G is suggested which is slightly more restrictive than at present. Published results for stresses due to local loads on branches in cylindrical vessels are compared with the values given by the charts.


Author(s):  
Bogdan S. Wasiluk ◽  
Douglas A. Scarth

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.


1993 ◽  
Vol 28 (3) ◽  
pp. 187-196 ◽  
Author(s):  
S J Hardy ◽  
A R Gowhari-Anaraki

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.


1944 ◽  
Vol 11 (3) ◽  
pp. A140-A148
Author(s):  
Leon Beskin

Abstract In this paper, stress distributions are determined around strengthened circular holes in plates submitted to edge loads at infinity. Various proportions of circular strengthenings are considered, and three conditions of applied edge loads are investigated; uniform hydrostatic stress, uniform shearing stress, uniform axial stress. Stress distributions are found by methods of theory of elasticity, and the results are given in the form of stress-concentration factors. In order to reduce the results to a common basis, the stress-concentration factors have been defined by the ratio of the critical stress, computed by the distortion-energy theory, to the critical stress at infinity, which is the critical stress in the plate without hole.


1996 ◽  
Vol 118 (3) ◽  
pp. 321-327 ◽  
Author(s):  
S. M. Tipton ◽  
J. R. Sorem ◽  
R. D. Rolovic

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.


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