Stresses at offset-oblique holes in thick-walled cylinders subjected to torsional loading

1980 ◽  
Vol 15 (4) ◽  
pp. 175-182 ◽  
Author(s):  
P Stanley ◽  
B V Day
Keyword(s):  
Shear Stress ◽  
Maximum Stress ◽  
Elastic Stress ◽  
Three Dimensional ◽  
Outer Edge ◽  
Torsional Loading ◽  
Stress Concentrations ◽  
Wide Range ◽  
Photoelastic Analysis ◽  
Geometric Variables

The paper describes a three-dimensional photoelastic analysis of a series of Araldite models, each containing five or six different offset-oblique holes positioned in such a way that there were no ‘interaction’ effects between neighbouring holes. The geometric parameters defining a hole were varied systematically and the elastic stress distribution around the outer edge of each hole was obtained. The stress data are presented in non-dimensional form in terms of the shear stress in a plain cylinder. The dependence of the maximum stress on the geometric variables is discussed and it is shown that the stress concentrations for a wide range of hole/cylinder parameters can be reasonably well predicted from flat plate data. In some cases the predictions are unconservative.

Three-dimensional photoelastic analysis in axially loaded thick plate with hole

1973 ◽  
Vol 8 (3) ◽  
pp. 220-227 ◽  
Author(s):  
N A Rubayi ◽  
V Yadava
Keyword(s):  
Circular Hole ◽  
Thick Plate ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Tensile Loading ◽  
Stress Concentrations ◽  
Precise Location ◽  
Stress Variation ◽  
Photoelastic Analysis ◽  
Different Thickness

In this study three-dimensional photoelasticity is used to analyse the stress variation through different layers of a thick plate containing a circular hole and subjected to uniform tensile loading. The effect of the thickness/diameter ratios on the stress concentrations with thickness is investigated. The experimental results are correlated with the existing three-dimensional theoretical solutions. The data establish, both experimentally and theoretically, the precise location of the maximum-stress layers in plates having different thickness/diameter ratios and thus resolves the discrepancies which existed in previous studies.

Roughness Element Geometry Required for Wind Tunnel Simulations of the Atmospheric Wind

1977 ◽  
Vol 99 (3) ◽  
pp. 480-485 ◽  
Author(s):  
I. S. Gartshore ◽  
K. A. De Croos
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Wind Tunnel ◽  
Roughness Element ◽  
Three Dimensional ◽  
Wall Stress ◽  
Wide Range ◽  
Drag Plate ◽  
Rough Boundaries ◽  
Single Figure

Using a data correlation for the wall stress associated with very rough boundaries and a semi-empirical calculation method, the shape of boundary layers in exact equilibrium with the roughness beneath them is calculated. A wide range of roughness geometries (two- and three-dimensional elements) is included by the use of equivalent surfaces of equal drag per unit area. Results can be summarized in a single figure which relates the shape factor of the boundary layer (its exponent if it has a power law velocity profile) to the height of the roughness elements and their spacing. New data for one turbulent boundary layer developing over a long fetch of uniform roughness is presented. Wall shear stress, measured directly from a drag plate is combined with boundary layer integral properties to show that the shear stress correlation adopted is reasonably accurate and that the boundary layer is close to equilibrium after passing over a streamwise roughness fetch equal to about 350 times the roughness element height. An example is given of the way in which roughness geometry may be chosen from calculated equilibrium results, for one particular boundary layer thickness and a shape useful for simulating strong atmospheric winds in a wind tunnel.

Three-Dimensional Elastic Stress Fields of Finite Thickness Plates with Elliptical Hole

2007 ◽  
Vol 353-358 ◽  
pp. 74-77
Author(s):  
Zheng Yang ◽  
Chong Du Cho ◽  
Ting Ya Su ◽  
Chang Boo Kim ◽  
Hyeon Gyu Beom
Keyword(s):  
Stress Concentration ◽  
Plane Strain ◽  
Plane Stress ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Maximum Stress ◽  
Elastic Stress ◽  
Finite Thickness ◽  
Plate Thickness ◽  
Three Dimensional

Based on detailed three-dimensional finite element analyses, elastic stress and strain field of ellipse major axis end in plates with different thickness and ellipse configurations subjected to uniaxial tension have been investigated. The plate thickness and ellipse configuration have obvious effects on the stress concentration factor, which is higher in finite thickness plates than in plane stress and plane strain cases. The out-of-plane stress constraint factor tends the maximum on the mid-plane and approaches to zero on the free plane. Stress concentration factors distribute ununiformly through the plate thickness, the value and location of maximum stress concentration factor depend on the plate thickness and the ellipse configurations. Both stress concentration factor in the middle plane and the maximum stress concentration factor are greater than that under plane stress or plane strain states, so it is unsafe to suppose a tensioned plate with finite thickness as one undergone plane stress or plane strain. For the sharper notch, the influence of three-dimensional stress state on the SCF must be considered.

scholarly journals Use of Multidimensional Models to Investigate Boundary Shear Stress through Meandering River Channels

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3506
Author(s):  
Timothy J. Randle
Keyword(s):  
Shear Stress ◽  
Three Dimensional ◽  
Field Studies ◽  
River Channels ◽  
Meandering River ◽  
Boundary Shear ◽  
Wide Range ◽  
Channel Curvature ◽  
Boundary Shear Stress ◽  
Multidimensional Models

Three-dimensional hydraulics were simulated through a wide range of synthetically generated meandering river channels to determine how channel curvature and width would correlate with the maximum boundary shear stress. Multidimensional models were applied, similar to a computational flume to simulate a wide range of 72 meandering channels, developed from sine-generated curves. Cannel sinuosity ranged from 1.1 to 3.0 and included five consecutive meander bends. Longitudinal slopes of the various channels spanned four orders of magnitude, while bankfull discharges spanned three orders of magnitude. Using results from one-half of the simulation sets, an empirical correlation was found to predict the maximum boundary shear stress as a function of dimensionless ratios of channel curvature and width. The remaining simulation sets were used for verification. Multidimensional models were used to simulate channel hydraulics to efficiently investigate a wide range of channel sinuosity, width/depth ratios, bankfull discharges, and valley slopes. When simulating such a wide range of channel conditions, multidimensional models offer a more efficiency method of generating consistent datasets than either field studies or physical modeling. This paper demonstrates how multidimensional models can be used to identify important hydraulic relationships that are otherwise difficult to determine.

Three-dimensional, elastic stress distribution in end-milled, keyed connections

1983 ◽  
Vol 18 (2) ◽  
pp. 143-149 ◽  
Author(s):  
H Fessler ◽  
M Eissa
Keyword(s):  
Elastic Stress ◽  
Three Dimensional ◽  
Empirical Equations ◽  
Two Dimensional ◽  
Stress Concentrations ◽  
Axial Distribution ◽  
Simple Method ◽  
Torque Transmission ◽  
Applied Torque ◽  
Stress Models

Three- and two-dimensional, photoelastic, frozen-stress models of Standard metric and inch keyed connections have been loaded in torsion. Results from models with three different key lengths are presented here and related to the axial distribution of torque transmission. Empirical equations for the elastic stress concentrations in the prismatic part of key and keyway at the positions of contact between key and shaft have been derived for any likely width, thickness, and length of key, keyway fillet size, and applied torque. A simple method of eliminating stress concentrations in the keyway end is described.

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 analysis of some nut-bolt connections with modifications to the external shape of the nut

1987 ◽  
Vol 22 (4) ◽  
pp. 187-193 ◽  
Author(s):  
E A Patterson ◽  
B Kenny
Keyword(s):  
Shear Stress ◽  
Stress Concentration ◽  
Outer Surface ◽  
Maximum Stress ◽  
Maximum Shear Stress ◽  
Three Dimensional ◽  
Fatigue Tests ◽  
Steel Connections ◽  
Circumferential Groove ◽  
Stress Study

The effect on the stress levels in an axially loaded bolt has been investigated for the case where a nut which incorporated a circumferential groove in its outer surface was used. It was found from a three-dimensional photoelastic frozen stress study that the modified nut reduced the maximum stress in the bolt by 5 per cent. The addition of a bevel to the load bearing face of this nut further reduced the maximum stress to 74 per cent of its value in a standard connection. It has been established that these modifications reduce the maximum shear stress in the roots of the nut threads, and that the stress concentration associated with the groove was smaller than the maximum stress concentration in both the nut and bolt thread roots. The increase indicated by photoelastic analyses in the strength of the connection produced by these modifications, has also been substantiated by fatigue tests of steel connections, but these results are not reported in this paper.

Application of a chamfer slab technology to reduce internal cracks of continuous casting bloom during soft reduction process

2019 ◽  
Vol 116 (6) ◽  
pp. 608 ◽  
Author(s):  
Nanfu Zong ◽  
Hui Zhang ◽  
Minglin Wang ◽  
Zhifang Lu
Keyword(s):  
Shear Stress ◽  
Tensile Stress ◽  
Continuous Casting ◽  
Three Dimensional ◽  
Reduction Process ◽  
Element Model ◽  
Maximum Tensile Stress ◽  
Stress Concentrations ◽  
Soft Reduction ◽  
The Right

The stress concentrations over the brittle temperature range (BTR) in the bloom continuous casting are the main reason of internal cracks. In order to analyze the stress distribution in the BTR of the blooms during soft reduction stage, a three-dimensional thermo-mechanical finite-element model with different corner structures (i.e. chamfer angle and chamfer length) was established. The relationship between corner structures, maximum tensile stress, as well as shear stress is analyzed, and the influence of corner structure of bloom on the internal cracks is studied. The results show that the tensile stress and the shear stress decreased gradually by properly adjusting the chamfer angle and the chamfer length of the bloom. Compared with the use of the right-angle bloom casting, the application of chamfer bloom casting is able to reduce the stress concentration over the BTR, therefore reduces the internal cracks. In addition, as a side benefit, the chamfer bloom casting can save energy required in deforming the bloom during the soft reduction process.

Three-dimensional photoelastic analysis of pile caps

1996 ◽  
Vol 31 (1) ◽  
pp. 35-42
Author(s):  
P Krishna Iyer ◽  
C Sam
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Pile Spacing ◽  
Stress Components ◽  
Photoelastic Investigation ◽  
Pile Caps ◽  
Photoelastic Analysis ◽  
The Individual ◽  
Significant Bearing

This paper presents a three-dimensional photoelastic investigation of two- and four-pile caps for different depth—pile spacing ratios. For the analysis, the pile caps were idealized as rectangular blocks subjected to patches of loading at the column and pile locations. The individual stress components, their maximum values and locations were determined. Graphs showing the variations of important normal and shear stress components across depth, non-dimensionalized with the applied column stress, were given. On the basis of the results obtained it is concluded that the factors which are not hitherto considered in the design of pile caps have a significant bearing on the stress distribution.

Effect of Base Parameters on Mechanical Properties of Cement Concrete Pavement Considering Interlayer Contact

2013 ◽  
Vol 857 ◽  
pp. 227-231
Author(s):  
Yan Cong Zhang ◽  
Ling Ling Gao ◽  
Sili Li
Keyword(s):  
Shear Stress ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Great Influence ◽  
Dimensional Structure ◽  
Winkler Foundation ◽  
Base Parameters ◽  
Stress Maximum ◽  
Cement Concrete Pavement ◽  
Layer Contact

Three-dimensional structure model on Winkler foundation considering inter layer contact status was established. The effect that base modulus, thickness and inter layer contact status between slab and base to maximum stress of slab bottom and base bottom, shear stress between slab and base, warping of slab was calculated. The results showed that: interlayer contact status had great influence on slab stress and warping. Maximum stress of slab bottom dropped while bonding status decreased and slab warping increased obviously while bonding status weakened. Base modulus was the primary factor for base stress. Maximum stress of base bottom increased while modulus increased, and decreased while bonding status weakened. Interlayer shear stress occurred mainly at slab edge, and decreased while the bonding status weakened, almost had no correlation to base modulus and thickness.

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