Stress concentration caused by an oblique round hole in a flat plate under uniaxial tension

1968 ◽  
Vol 3 (2) ◽  
pp. 98-102 ◽  
Author(s):  
H W McKenzie ◽  
D J White
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
Elliptical Hole ◽  
Round Hole ◽  
Flat Plates ◽  
Reasonable Estimate ◽  
Load Carrying ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Plate Width

Stress-concentration factors have been determined for oblique holes in flat plates by a method using frozen-stress photoelasticity. The ellipses formed at the intersection of the hole and the plate surfaces had their major axes perpendicular to the direction of application of the load. The maximum stress-concentration factor was found to increase with increasing angle of obliquity with respect to the normal to the plate but the experimental factors were found to be considerably lower than those predicted from a theory of Ellyin et al. Graphs are given which enable maximum stress-concentration factors to be obtained for oblique holes having a ratio of hole diameter to plate width of 0.1. It was found that, for the models tested, elliptical hole data gave a reasonable estimate of the maximum stress-concentration factors based on net area. Removing the feather edge of the hole, by applying various edge radii, did not alter the stress concentration appreciably except in so far as load-carrying area was reduced.

Stress Analysis of Holes in Thick Plates

2004 ◽  
Vol 1-2 ◽  
pp. 153-158 ◽  
Author(s):  
S. Quinn ◽  
Janice M. Dulieu-Barton
Keyword(s):  
Stress Concentration ◽  
Stress Analysis ◽  
Uniaxial Tension ◽  
Plane Stress ◽  
Plate Surface ◽  
Flat Plates ◽  
Thick Plates ◽  
Concentration Factors ◽  
Stress Concentration Factors

A review of the Stress Concentration Factors (SCFs) obtained from normal and oblique holes in thick flat plates loaded in uniaxial tension has been conducted. The review focuses on values from the plate surface and discusses the ramifications of making a plane stress assumption.

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.

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.

Stress Concentration Factors in Shouldered Shafts Subjected to Combinations of Flexure and Torsion

1968 ◽  
Vol 90 (2) ◽  
pp. 301-307 ◽  
Author(s):  
H. G. Rylander ◽  
P. M. A. daRocha ◽  
L. F. Kreisle ◽  
G. J. Vaughn
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
Small Diameter ◽  
Bending Moment ◽  
Pure Bending ◽  
Principal Stresses ◽  
Torsional Loads ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Experimental Values

Geometric stress concentration factors were determined experimentally for shouldered aluminum shafts subjected to combinations of flexural and torsional loads. Diameter ratios were varied from 0.42 to 0.83, and fillet radius to small diameter ratios were varied from 0.1 to 0.7 with bending moment to torque ratios varying over a range from 1:4 to 4:1. Experimental values for the stress concentration factors were obtained by using birefringent coatings and a reflection polariscope. Strain gage measurements and torsional relaxation solutions were used to verify some of the polariscope data. For the cases considered, the static geometric stress concentration factor was between 1.11 and 1:50 for pure torsion, between 1.08 and 1.46 for pure bending, and between 1.09 and 1.50 for combined torsion and bending. The directions of the principal stresses on the surface of the shouldered shafts do not change due to the presence of the discontinuity for a particular specimen and type of loading. Also, the location of the maximum stress in the fillet of a particular specimen under a certain type of loading does not change as the magnitude of the load is varied, but it does vary with the type of loading.

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.

Stress-Concentration Factors in Shafts With Transverse Holes as Found by the Electroplating Method

1955 ◽  
Vol 22 (2) ◽  
pp. 193-196
Author(s):  
H. Ōkubo ◽  
S. Satō
Keyword(s):  
Stress Concentration ◽  
Outer Surface ◽  
Maximum Stress ◽  
Accurate Determination ◽  
Slicing Method ◽  
Concentration Factors ◽  
Mathematical Difficulties ◽  
Stress Concentration Factors ◽  
Maximum Stresses

Abstract In this paper the torsion of shafts with transverse holes has been investigated experimentally. Usual methods for stress measurements, such as the method of brittle coatings and the use of sensitive extensometers, are not applied effectively to the present problem because the maximum stress occurs in the bore and does not occur on the outer surface of the shaft. The stress may be measured by the stress-freezing and slicing method but we cannot expect too much from this method for the accurate determination of the stress when the diameter of the hole is comparatively small. In treating the problem theoretically, considerable mathematical difficulties are encountered on account of its axially nonsymmetrical nature. The electroplating method recently developed by one of the authors (1), however, has been proved to be useful in this case, so the maximum stresses in shafts are measured by this method and the stress-concentration factors are found for various diameters of the hole.

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.

New Metrics for Pit Shape Characterization

2014 ◽  
Author(s):  
Virginia G. DeGiorgi ◽  
Siddiq M. Qidwai ◽  
Nithyanand Kota
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
Multiple Parameters ◽  
Retinal Blood Vessels ◽  
Geometric Factors ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
The Individual ◽  
Individual Grains ◽  
Shape Characterization

Currently a variety of approaches are used to match stress concentration factors with corrosion pit geometry. The majority of these approaches use standardized stress concentration factors, such as concentration factors for circles or ellipses, to estimate the maximum stress values along the pit front. These factors are based on regular geometric shapes. Pits that form in a microstructure are influenced by the individual grains surrounding the pit. These pits often do not have simple shapes. Use of standardized geometric factors do not capture the geometric complexity of the pit. Rather than a single parameter, such as a the aspect ratio of an ellipse, multiple parameters may be required to define the extent and variation in localized curvature along a pit front within a microstructure. Maximum depth and curvature are just two possible candidate metrics. In addition the authors looked to the medical field for potential metrics to adequately describe the convoluted nature of the pit front. Several methods have been developed to mathematically define the serpentine twists in diseased retinal blood vessels. In this work the authors present a methodology for determining characteristics including tortuosity of computationally predicted pit shapes embedded in microstructures. Ultimately it is hoped that maximum curvature, pit tortuosity and other geometric based metrics can be combined to predict the maximum rise in stress associated with a pit embedded in a microstructure.

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.

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