Stress Concentrations in Circular Tubular Members Containing Local Damage

1989 ◽  
Vol 111 (4) ◽  
pp. 278-284 ◽  
Author(s):  
C. K. W. Tam ◽  
J. G. A. Croll
Keyword(s):  
Analytical Method ◽  
Elastic Stress ◽  
Geometric Errors ◽  
Local Damage ◽  
Stress Concentrations ◽  
Load Function ◽  
Axially Loaded ◽  
Local Dent

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.

Analytical Method for Settlement of Axially Loaded Compressible Pile

2012 ◽  
Vol 42 (2) ◽  
pp. 75-86
Author(s):  
Virendra Singh ◽  
Sushil Kumar Lal
Keyword(s):  
Analytical Method ◽  
Axially Loaded

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 Concentrations at the Rounded Edges of a Shaft-Hub Interference Fit Expressed in Terms of a Coefficient Normalizing the Coupling Geometry and the Young’s Modulus Effects

2012 ◽  
Author(s):  
Antonio Strozzi ◽  
Andrea Baldini ◽  
Matteo Giacopini ◽  
Enrico Bertocchi ◽  
Luca Bertocchi
Keyword(s):  
Stress Concentration ◽  
Young’S Modulus ◽  
Elastic Stress ◽  
Young's Modulus ◽  
Outer Radius ◽  
Stress Concentrations ◽  
Interference Fit ◽  
Press Fit ◽  
Fillet Radius ◽  
Inner Radius

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.

Yielding and Plastic Flow in Stainless Steel: A TEM Study of the Evolution of Microstructure Associated with the Stress-Strain Diagram

1980 ◽  
Vol 38 ◽  
pp. 386-387
Author(s):  
L.E. Murr ◽  
S-H. Wang
Keyword(s):  
Grain Boundaries ◽  
Elastic Stress ◽  
Metals And Alloys ◽  
Strain Diagram ◽  
Stress Concentrations ◽  
Polycrystalline Metals ◽  
Pile Up ◽  
Local Slip ◽  
Evolution Of Microstructure

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.

Effect of Longitudinal Fastener Stiffness on Fastening System Loading - Initial Findings

2021 ◽  
Author(s):  
Christian J. Khachaturian ◽  
Marcus S. Dersch ◽  
J. Riley Edwards ◽  
Matheus Trizotto
Keyword(s):  
North America ◽  
Analytical Model ◽  
Fatigue Failure ◽  
Analytical Method ◽  
Vertical Load ◽  
Stress Concentrations ◽  
Laboratory Experimentation ◽  
The Past ◽  
Track Stiffness ◽  
Fatigue Failures

Abstract Over the past 20 years, there have been at least 10 derailments due to spike fatigue failures in North America. Researchers believe that fatigue failure is caused by a combination of lateral and longitudinal spike loading. The literature indicates the vertical load and fastener friction must be considered when estimating failure locations. Though the in-track vertical, lateral, and longitudinal fastener forces have been quantified at a location that has experienced spike failures, there is a need to account for additional fasteners and track locations. Fastening systems can affect track stiffness, thus, laboratory experimentation was performed to quantify stiffness of multiple fastening systems. This data was input into an analytical model which quantified the effect of stiffness on longitudinal fastener loading. The data indicate there is significant variance in fastening system stiffness within, and between, systems. However, this variation in fastener stiffness has a reduced effect on the load transferred to the fastening system. More work is needed to validate this in the lab or field given variability within a system could lead to stress concentrations that are not fully captured using the current idealized analytical method.

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.

The Static and Fatigue Torsion Strengths of Various Steels with Circular, Square, and Rectangular Sections

1940 ◽  
Vol 143 (1) ◽  
pp. 237-246 ◽  
Author(s):  
E. G. Holley
Keyword(s):  
Cross Sections ◽  
Elastic Stress ◽  
High Stress ◽  
Stress Distributions ◽  
Static Properties ◽  
Stress Concentrations ◽  
Distribution Of Stress ◽  
Static Torsion

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.

scholarly journals Fatigue response of aircraft wing root joints under limit cycle oscillations

2021 ◽  
Author(s):  
Behzad Yousefirad
Keyword(s):  
Cyclic Loading ◽  
Limit Cycle ◽  
Damage Accumulation ◽  
Elastic Stress ◽  
Mean Stress ◽  
Plastic Strains ◽  
Limit Cycle Oscillations ◽  
Stress Concentrations ◽  
Aircraft Wing ◽  
Initial Cracks

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.

Analytical Study of Perforation Damage to Reinforced Concrete Slabs Subjected to Oblique Impact by Projectiles With Different Nose Shapes

2020 ◽  
Author(s):  
Zuoyi Kang ◽  
Yukihiko Okuda ◽  
Akemi Nishida ◽  
Haruji Tsubota ◽  
Yinsheng Li
Keyword(s):  
Reinforced Concrete ◽  
Analytical Method ◽  
Oblique Impact ◽  
Local Damage ◽  
Target Structure ◽  
Rc Structures ◽  
Projectile Impact ◽  
Impact Tests ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs

Abstract Considerable research has been carried out to establish a rational assessment method for nuclear power plants against local damage caused by an accidental projectile impact. Most of the empirical formulas that have been proposed seek to quantitatively investigate local damage to reinforced concrete (RC) structures caused by a rigid projectile impact. These formulas have been derived based on impact tests performed perpendicular to the target structure, while only a few impact tests oblique to the target structure have been studied. This study aims to propose a new formula for evaluating local damage to RC structures caused by oblique impact based on experimental and simulation results. At present, we have validated an analytical method via comparison with experimental results and have conducted simulation analyses of oblique impact assessments on RC slabs using various projectiles with flat nose shapes. In this study, the same analytical method will be used to investigate perforation damage to RC slabs subjected to oblique impact by projectiles with hemispherical nose shapes. In this paper, the effects of projectiles’ nose shapes on perforation damage to RC slabs, the residual velocity of projectiles and the time history of energy transmission will be discussed.

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