Reduction of elastic stress concentrations in end-milled keyed connections

1983 ◽  
Vol 23 (4) ◽  
pp. 401-408 ◽  
Author(s):  
M. Eissa ◽  
H. Fessler
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.


1989 ◽  
Vol 111 (4) ◽  
pp. 278-284 ◽  
Author(s):  
C. K. W. Tam ◽  
J. G. A. Croll

Offshore structural circular tubular members suffering from local dent damage can develop extreme stresses at locations around the dent area. An analytical method for the prediction of elastic stress concentrations in locally damaged circular tubular members is presented. The method is based upon replacing geometric errors with an appropriately chosen load function to be applied to the perfect member for analysis. A simpler approach based upon an axisymmetric analysis, suitable for speedy assessment of the damage effects, is also presented. Axially loaded tubulars containing an idealized dent under stress and displacement-controlled situations are included.


Author(s):  
Antonio Strozzi ◽  
Andrea Baldini ◽  
Matteo Giacopini ◽  
Enrico Bertocchi ◽  
Luca Bertocchi

The elastic stress concentrations developed from the keyless, frictionless, static press-fit of a solid shaft into a hub with bore rounded edges are addressed. Derived from an analytical approach, a normalising parameter Φ is employed that accounts for the combined effects on the hub stress concentration of the fillet radius of the hub bore, the shaft radius, the interference, and the Young’s modulus. Compiled with the aid of Finite Elements, several design charts are presented that report the elastic stress concentrations within the hub versus the normalising parameter Φ. Each curve is valid for prescribed ratios of a) the hub inner radius to the outer radius, and b) the fillet radius to the shaft radius. An approximating expression of ample validity is also presented for a prompt evaluation of the hub stress concentration factor.


Author(s):  
L.E. Murr ◽  
S-H. Wang

In spite of the fascination with dislocation pile-ups and the description of flow in metals and alloys based upon pile-up models, evidence has existed for decades suggesting that slip often if not always starts at grain boundaries in polycrystalline metals and alloys. Hook and Hirth showed that elastic incompatibility could result in local slip at the boundary between bicrystals, and their contention that local elastic stress concentrations at grain boundaries would aid slip nucleation was confirmed by Carrington, etal. Ashby has also described polycrystalline metals and alloys as plastically non-homogeneous because gradients of plastic deformation are imposed by the grain boundaries, and Murr has discussed the role of grain boundary ledges as initial sources for dislocations when polycrystalline metals and alloys are deformed. Brentnall and Rostoker earlier concluded that grain boundaries are both sources of early dislocations and barriers limiting their movement at higher stresses, and that slip is confined to grains in which it was initiated until the yield point is reached.


1980 ◽  
Vol 15 (4) ◽  
pp. 175-182 ◽  
Author(s):  
P Stanley ◽  
B V Day

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.


1940 ◽  
Vol 143 (1) ◽  
pp. 237-246 ◽  
Author(s):  
E. G. Holley

The paper records the results of a research into the comparative elastic and fatigue torsion strengths of bars of circular, square, and rectangular cross-sections. The static torsion tests reveal that in the case of square and rectangular sections the use of enlarged ends leads to discrepancies between the experimental and theoretical values of the elastic torsion strengths. The fatigue torsion tests disclose astonishing fatigue weaknesses in square and rectangular bars, the weaknesses being masked when the ends of the specimens are enlarged. The fatigue torsion strengths of square and rectangular bars are compared with the fatigue torsion strengths of circular shafts with keyways and it is emphasized that outstanding fatigue weakness may be associated with certain forms of stress distributions even when high stress concentrations are absent. Consideration is given to the value of the static properties of metals as safe criteria of fatigue strengths. In an appendix the problem of the raising of the elastic stress in a material when the distribution of stress is uneven is discussed.


2021 ◽  
Author(s):  
Behzad Yousefirad

When wing root attachments are subject to cyclic loading during a flight, slipbands are produced by fatique. The density of these slipbands increases with the advancing of the fatigue process and initial cracks appear within the persistent slipbands. This project investigates the fatigue response of a titanium alloy wing root joint under different loading spectra during limit-cycle oscillations by the strain-life approach. Although wing root attachments are designed such that the nominal loads remain elastic, stress concentrations often cause plastic strains to develop in the vincinity of notches. Subsequently, wing loads caused by limit-cycle oscillations lead to fatique damage accumulation. This project's results lead to the conclusion that cyclic loading during limit-cycle oscillations can cause fatigue damage in wing root joints. Tensile mean stress is detrimental to the fatique life of wing root joints, while compressive mean stress is beneficial.


1983 ◽  
Vol 18 (2) ◽  
pp. 143-149 ◽  
Author(s):  
H Fessler ◽  
M Eissa

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.


2000 ◽  
Vol 35 (2) ◽  
pp. 143-147 ◽  
Author(s):  
P Stanley ◽  
A G Starr

An empirical equation has been obtained for the elastic stress concentration factor at an isolated oblique circular-cylindrical hole in a thick flat plate subjected to a uniform, arbitrarily oriented uniaxial tension. The equation is presented and its development is outlined in this note.


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