A study of stress concentrations in solids with circular holes by three-dimensional special hybrid stress finite elements

1990 ◽  
Vol 25 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Z-S Tian
Keyword(s):  
Finite Elements ◽  
Three Dimensional ◽  
Stress Concentrations ◽  
Equilibrium Equations ◽  
Circular Holes ◽  
Concentration Factors ◽  
Solid Finite Elements ◽  
Stress Concentration Factors ◽  
Limiting Case ◽  
Free Cylindrical Surface

Four kinds of 12-node solid finite elements with two parallel faces and one traction-free cylindrical surface have been developed based on the assumed stress hybrid method. Cylindrical coordinates are used so that the assumed stresses satisfy the equilibrium equations as well as the traction-free condition over the cylindrical boundary. In the limiting case of plane stress the assumed stresses also satisfy the compatibility conditions. Examples have indicated that these present special solid finite elements are far superior in predicting the distributions of the circumferential stresses and the stress concentration factors for solids with circular holes.

Stress Concentration Effects in Short Cylindrical Vessels With Holes Subjected to Tension: A Complete Account

2005 ◽  
Vol 127 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Nando Troyani ◽  
Nelson Jaimes ◽  
Gaetano Sterlacci ◽  
Carlos J. Gomes
Keyword(s):  
Stress Concentration ◽  
Elastic Shell ◽  
Critical Factor ◽  
Circular Cylinders ◽  
Stress Concentrations ◽  
Concentration Effects ◽  
Analysis And Design ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors

Whenever regular geometric discontinuities are present the so called stress concentration factors concept is widely used in both analysis and design of loaded components especially when subjected to fatigue, frequently the working condition of vessels. However, recent observations suggest that the influence of member length on the magnitude of the stated factors was not considered in previous analyses. In this work, this observation was studied in the context of cylindrical vessels and it was found that in this case, as well, length could be a critical factor when computing stresses developed as a result of externally applied loads. Accordingly, the values of the finite element calculated theoretical stress concentration factors are computed, for the case of short circular cylinders with circular holes subjected to axial tension, in the context of elastic shell theory, and are presented in a fashion similar to existing published results. It is shown that significantly larger stress concentrations appear for shorter members. The transition length concept defining the threshold between long cylinders and short cylinders is discussed in the context of this study and reported as well.

Effect of Length on Stress Concentration for Short Cylindrical Members With Holes

2004 ◽  
Author(s):  
Nando Troyani ◽  
Gaetano Sterlacci ◽  
Nelson Jaimes ◽  
Carlos J. Gomes
Keyword(s):  
Stress Concentration ◽  
Critical Factor ◽  
Circular Cylinders ◽  
Stress Concentrations ◽  
Analysis And Design ◽  
Axial Tension ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Novel Concept

As is well known stress concentration will appear in any application where some form of geometric discontinuity is present. To deal with such situations the so called Stress Concentration Factors (SCF) concept was developed and is widely used in both analysis and design of loaded components especially when subjected to fatigue, usually the working condition of vessels. However, recent observations suggest that the influence of member length on the magnitude of the stated SCF’s was not considered. In this work, this observation was studied in the context of cylindrical vessels and it was found that in this case, as well, length could be a critical factor when computing stresses developed as a result of externally applied loads. The values of the Finite Element (FE) calculated Theoretical Stress Concentration Factors (TSCF’s) are computed, for the case of short circular cylinders with circular holes subjected to axial tension, and presented in a fashion similar to existing published results. It is shown that significantly larger stress concentrations appear for short members. The novel concept of transition length, that defines the threshold between long plates and short plates, is discussed in the context of this study and reported as well.

Stress-Concentration Factors Around a Central Circular Hole in a Plate Loaded Through Pin in the Hole

1940 ◽  
Vol 7 (1) ◽  
pp. A5-A9 ◽  
Author(s):  
M. M. Frocht ◽  
H. N. Hill
Keyword(s):  
Stress Concentration ◽  
Hole Diameter ◽  
Finite Width ◽  
Center Line ◽  
Strain Gages ◽  
Stress Concentrations ◽  
Circular Holes ◽  
Concentration Factors ◽  
Institute Of Technology ◽  
Stress Concentration Factors

Abstract This paper deals with factors of stress concentrations in plates of finite width with central circular holes loaded through pins or rivets. Two sets of results are presented, one from oversize aluminum specimens in which the stresses were determined from strain-gage measurements, the other, from photoelastic tests with small bakelite models. The two investigations were conceived and executed independently. The tests involving the use of strain gages were made at Aluminum Research Laboratories and the photoelastic tests were made at the Photoelastic Laboratory of the Carnegie Institute of Technology. While most of the tests involved plates loaded through a single pin in a hole on the longitudinal center line of the plate, several tests were made on plates loaded through two pins symmetrically situated about the center line of the plate. Numerical values for the stress-concentration factor k are given for ratios of hole diameter to width of plate (2r/D) ranging from 0.086 to 0.76.

Analysis of Stress Concentrations in Thick Cylinders With Sideholes and Crossholes

1972 ◽  
Vol 94 (3) ◽  
pp. 815-824 ◽  
Author(s):  
J. C. Gerdeen
Keyword(s):  
Stress Concentration ◽  
Stress Concentrations ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Experimental Values ◽  
Pressure Stress ◽  
Shrink Fit ◽  
Outside Diameter ◽  
Theoretical Results

An approximate theoretical analysis is presented for the determination of stress concentration factors in thick walled cylinders with sideholes and crossholes. The cylinders are subjected to both internal pressure and external shrink-fit pressure. Stress concentration factors are plotted as functions of the geometrical ratios of outside diameter-to-bore diameter, and bore diameter-to-sidehole diameter. Theoretical results are compared to experimental values available in the literature and results of experiments described in a separate paper.

Stress Concentration Factors in Auxetic Rods and Plates

2013 ◽  
Vol 394 ◽  
pp. 134-139 ◽  
Author(s):  
Teik Cheng Lim
Keyword(s):  
Stress Concentration ◽  
Circumferential Stress ◽  
Axial Direction ◽  
Thin Plates ◽  
Auxetic Materials ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Future Work ◽  
Poissons Ratio

Auxetic materials are solids that possess negative Poissons ratio. Although rare, such materials do occur naturally and also have been artificially produced. Due to their unique properties, auxetic materials have been extensively investigated for load bearing applications including in biomedical engineering and aircraft structures. This paper considers the effect of Poissons ratio on the stress concentration factors on rods with hyperbolic groove and large thin plates with circular holes and rigid inclusions. Results reveal that the use of auxetic materials is useful for reducing stress concentration in the maximum circumferential stress of the rods with grooves, and in plates with circular holes and rigid inclusions. However, the use of auxetic materials increases the stress concentration in the axial direction of the rod. Therefore a procedure to accurately select and/or design materials with precise negative Poissons ratio for optimal design is suggested for future work.

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 concentrations due to axial tension and bending of loaded axisymmetric projections

1983 ◽  
Vol 18 (1) ◽  
pp. 7-14 ◽  
Author(s):  
T H Hyde ◽  
B J Marsden
Keyword(s):  
Stress Concentration ◽  
Diameter Ratio ◽  
The Finite Element Method ◽  
Stress Concentrations ◽  
Axial Tension ◽  
Bending Loads ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
D Values ◽  
Existing Data

The finite element method has been used to investigate the behaviour of axisymmetric loaded projections (e.g., bolts) subjected to axial tension and bending. The results show that existing data for stepped shafts, which have the axial tension and bending loads applied remote from the region of the step, cannot be applied to loaded projections with the same geometry. For h/d (head thickness to shank diameter ratio) values greater than 0.66 and 0.41 for axial tension and bending, respectively, the stress concentration factors are independent of h/d, load position, and D/d (head diameter to shank diameter ratio) for D/d in the range 1.5 ≤ D/d ≤ 2.0. Smaller h/d values result in large increases in the stress concentration factors due to dishing of the head.

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 in a Hybrid Composite Sheet

1983 ◽  
Vol 50 (4a) ◽  
pp. 845-848 ◽  
Author(s):  
H. Fukuda ◽  
T. W. Chou
Keyword(s):  
Stress Concentration ◽  
Hybrid Composite ◽  
Fiber Strength ◽  
Series Representation ◽  
High Modulus ◽  
Composite Sheet ◽  
Stress Concentrations ◽  
Low Modulus ◽  
Concentration Factors ◽  
Stress Concentration Factors

This paper examines the load redistribution in a hybrid composite sheet due to fiber breakage. The hybrid composite contains both high modulus and low modulus fibers arranged in alternating positions. Stress concentration factors for both types of fibers immediately adjacent to a group of fractured fibers have been evaluated. The method of influence function and Fourier series representation are adopted. Results of stress concentration factors are presented in terms of the number of fractured fibers and their geometric arrangements. Reduction of the stress concentration factor of the high modulus fibers when dispersed among the low modulus fibers provides a theoretical explanation of the observed “hybrid effect.” The present analysis can be readily incorporated into a failure model taking into account the statistical nature of fiber strength.

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