A simplified approach to calculating stresses due to radial loads and moments applied to branches in cylindrical pressure vessels (calculations to BS 5500, Appendix G)

1981 ◽  
Vol 16 (4) ◽  
pp. 217-226 ◽  
Author(s):  
M A Teixeira ◽  
R D McLeish ◽  
S S Gill
Keyword(s):  
Stress Concentration ◽  
Elastic Stress ◽  
Pressure Vessels ◽  
Geometrical Parameters ◽  
Local Loads ◽  
Simplified Approach ◽  
Concentration Factors ◽  
Stress Concentration Factors

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.

scholarly journals Stress Concentration Factors for Welded Plate T-Joints Subjected to Tensile, Bending and Shearing Loads

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 546
Author(s):  
Krzysztof L. Molski ◽  
Piotr Tarasiuk
Keyword(s):  
Stress Concentration ◽  
Plate Thickness ◽  
Percentage Error ◽  
Geometrical Parameters ◽  
T Joints ◽  
Loading Mode ◽  
Weld Toe ◽  
Concentration Factors ◽  
Parametric Expression ◽  
Stress Concentration Factors

The paper deals with the problem of stress concentration at the weld toe of a plate T-joint subjected to axial, bending, and shearing loading modes. Theoretical stress concentration factors were obtained from numerical simulations using the finite element method for several thousand geometrical cases, where five of the most important geometrical parameters of the joint were considered to be independent variables. For each loading mode—axial, bending, and shearing—highly accurate closed form parametric expression has been derived with a maximum percentage error lower than 2% with respect to the numerical values. Validity of each approximating formula covers the range of dimensional proportions of welded plate T-joints used in engineering applications. Two limiting cases are also included in the solutions—when the weld toe radius tends to zero and the main plate thickness becomes infinite.

Elastic Stress Concentrations for the Torsion of Hollow Shouldered Shafts Determined by an Electrical Analogue

1964 ◽  
Vol 15 (1) ◽  
pp. 83-96 ◽  
Author(s):  
K. R. Rushton
Keyword(s):  
Stress Concentration ◽  
Elastic Stress ◽  
Plastic Region ◽  
Stress Concentrations ◽  
Electrical Analogue ◽  
Shoulder Diameter ◽  
Concentration Factors ◽  
Stress Concentration Factors

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.

Stress concentration factors in compression—fit couplings

2010 ◽  
Vol 224 (6) ◽  
pp. 1143-1152 ◽  
Author(s):  
D Croccolo ◽  
N Vincenzi
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
External Pressure ◽  
Geometrical Parameters ◽  
Boundary Zone ◽  
Finite Element Analyses ◽  
Axially Symmetric ◽  
Numerical Investigations ◽  
Concentration Factors ◽  
Stress Concentration Factors

The aim of the present work is to define the maximum stress generated by the coupling of axially symmetric and continuous shafts press-fitted into axially symmetric hubs. The theoretical stresses given by the well-known formulae of the thick-walled cylinders theory are constant on the whole coupling surface, but if the shaft extends beyond the hub there is a stress concentration factor on the boundary zone. This occurrence is confirmed by finite element analyses performed by the authors on several different shaft—hub couplings. The analysed couplings have the shaft extended beyond the hub, the shafts press-fitted into the hubs, and both shafts and hubs loaded by an external pressure and an internal pressure. The stress concentration factors have been calculated in this work and their expressions have been derived as a function of some tensile and geometrical parameters. By combining the thick-walled cylinders theory with the proposed formulae, it is possible to evaluate the maximum stress located at the end of the hub without performing any numerical investigations.

Theoretical Stresses Near a Circular Opening in a Flat Plate, Reinforced With a Cylindrical Outlet

1959 ◽  
Vol 81 (2) ◽  
pp. 189-200 ◽  
Author(s):  
Everett O. Waters
Keyword(s):  
Stress Concentration ◽  
Flat Plate ◽  
Circular Hole ◽  
Wall Thickness ◽  
Plate Thickness ◽  
Pressure Vessels ◽  
Circular Opening ◽  
Concentration Factors ◽  
Stress Concentration Factors

Formulas are derived for stresses in the neighborhood of a circular hole in a flat plate, when the opening is reinforced with a cylindrical outlet such as a pipe or nozzle. The plate is loaded in tension, either uniformly in all directions, or with transverse and longitudinal tensions in the ratio of 2:1 as is the case in cylindrical pressure vessels. Consideration is given to the possibility of “balanced reinforcement” by adding material on both sides of the plate. Tables and graphs are included for the use of designers who wish to find the stress-concentration factors for different combinations of plate thickness, outlet-wall thickness, and outlet diameter.

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.

Sign in / Sign up

Export Citation Format

Share Document