Stress Analysis of O.D. Notched Thick-Walled Cylinders Subjected to Internal Pressure or Thermal Loads

1981 ◽  
Vol 103 (1) ◽  
pp. 76-84 ◽  
Author(s):  
J. A. Kapp ◽  
G. A. Pflegl
Keyword(s):  
Stress Concentration ◽  
Residual Stresses ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Maximum Stress ◽  
Additional Result ◽  
Finite Element Stress Analysis ◽  
Temperature Loads

Finite element stress analysis has been performed to determine the effects of two O.D. notch configurations in a cylinder subjected to internal pressure, or containing autofrettage residual stress. The effects on the residual stresses were determined by simulating these stresses with equivilent temperature loads. The results show that the deeper of the two notch cofigurations is far more severe resulting in a maximum stress concentration factor of 6.6. The shallower notch has a maximum stress concentration factor of 3.7. An additional result is that by introducing notches in autofrettaged cylinders a significant amount of the residual stresses are relieved which indicates that smaller applied pressures can be applied before yielding occurs. The results also show that the possibility of O.D. initiated fatigue failure is greatly increased.

scholarly journals Stress concentration and optimal design of pinned connections

2019 ◽  
Vol 54 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Niels Leergaard Pedersen
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Mechanical Engineering ◽  
Maximum Stress ◽  
Civil Engineering ◽  
Three Dimension ◽  
Element Analysis ◽  
Standard Design ◽  
Connection Type

A pinned connection or lug joint is a common connection type used both in civil engineering and mechanical engineering. In civil engineering, this connection is used for assembling truss members, and in mechanical engineering, this connection type is widely used in machine elements. The standard design is with a circular pin. The stress concentration factor size depends on the tolerances between pin and assembled parts and also by the three-dimensional design. Relatively different maximum stress values are seen depending on the modelling being done in two dimension (with assumptions) or in full three dimension. The focus in the present article is on the two-dimensional design and minimizing the maximum stress. It is shown that not only the contact geometry is important for reducing the stress, the external design is equally important. By finite element analysis including contact modelling, it is shown that reduction in the stress concentration factor of up to 18% is possible.

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.

Elastic Stress Concentration Factors (Kt) by Stress Gradient Method Using FEA

1996 ◽  
Author(s):  
Ajay Garg ◽  
Ravi Tetambe
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Maximum Stress ◽  
Elastic Stress ◽  
Stress Gradient ◽  
Nominal Stress ◽  
Element Analysis

Abstract The elastic stress concentration factor, Kt, is critical in determining the life of machines, especially in the case of notched components experiencing high cycle fatigue. This Kt is defined as the ratio of the maximum stress (σmax) at the notch to the nominal stress (σnom) in the region away from the notch effect. For simple geometries such as, plate with a hole, calculation of Kt from either closed form solution or from making simple but valid assumptions is possible [1,2]. However, for complex machine components such data is usually not available in the literature. Using Kt values from the simple geometries may lead to either over or under estimation of the real Kt for such complex geometries. Such error can then further lead to a substandard product or a product which is overdesigned and expensive. Present paper outlines a methodology for computing reasonably accurate elastic stress concentration factor, Kt, using finite element analysis (FEA) tool. The maximum stress (σmax) is readily available from the finite element analysis. The nominal stress (σnom) near the stress concentration is however can not be directly extracted from the FEA results. A novel approach of estimating reasonably accurate σnom is presented in this paper. This approach is based on selecting the correct path at the stress concentration region, post processing the stress and the stress gradient results along that path and identifying the cut of point where stress concentration effect begins to take place. This methodology is first validated using two examples with known Kt and later applied to a real world problem.

Use of Tubular Joint Stress Concentration Factor Parametric Formulae in the Analysis of Large Diameter Pipework Connections

2000 ◽  
Author(s):  
R. M. Andrews ◽  
S. Wheat ◽  
M. Brown ◽  
C. Fowler
Keyword(s):  
Stress Concentration ◽  
Stress Analysis ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Large Diameter ◽  
Joint Stress ◽  
Tubular Joints ◽  
Tubular Joint ◽  
Potential Use ◽  
Pipe Joint

Parametric formulae derived for offshore structural tubular joints have been assessed for potential use for estimating stress intensification factors for pipe stress analysis. The background to these equations is given and comparisons made for a range of typical geometries. Despite the absence of a “plug” of material in a pipe joint, the tubular joint equations appear suitable for the estimation of stress intensification factors for fabricated tees subjected to moment loading of the branch. It is considered that this approach should be investigated further by code developers.

The Parametrical Stress Analysis of Tubular T Joints

1985 ◽  
Vol 107 (4) ◽  
pp. 473-478
Author(s):  
T.-Y. Chen ◽  
B.-Z. Chen ◽  
Y.-Q. Wang
Keyword(s):  
Experimental Data ◽  
Stress Concentration ◽  
Stress Analysis ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Axial Loading ◽  
Geometric Parameters ◽  
T Joints ◽  
Data Tables ◽  
The Relationship

The relationship between the geometric parameters of α, β, γ and τ of tubular T joints and chord stress concentration factor, SCF, has been investigated. With the use of calculated values as well as experimental data tables were compiled for a wide variety of cases when axial loading on the branch is applied. Finally, a probability analysis is given as to the reliability of using a particular SCF value.

Reinforced discontinuous bend subjected to uniform internal pressure: Effect of reinforcing ring stiffness

1973 ◽  
Vol 8 (2) ◽  
pp. 77-82 ◽  
Author(s):  
M Holland ◽  
N Barlow ◽  
H Mitchell
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Maximum Stress ◽  
Pressure Effect ◽  
Strain Gauges ◽  
Membrane Stress ◽  
Constant Depth ◽  
Elliptical Ring ◽  
Stress Profiles

This paper deals with the results of an experimental study undertaken to assess the stress-reducing effect of internally bracing a traditional constant-depth elliptical reinforcing ring. Stress profiles, calculated from strain readings recorded by electrical-resistance foil strain gauges bonded to inner and outer surfaces of the cylindrical limbs of model Araldite bends, are presented for four reinforcement conditions: constant-depth (traditional) elliptical ring; constant-depth ring with internal cruciform bracing; constant-depth ring with a single brace across the minor diameter; perfectly rigid reinforcing plate. When a traditional reinforcing ring was used the greatest stress-concentration factor (referring to circumferential membrane stress remote from the discontinuity as unity) was found to be 4.15. This was reduced to 2.90 by the use of a ring with a single minor-diameter brace and was further reduced to 2.70 when a ring having a cruciform brace set across major and minor diameters was used. The effect of an infinitely rigid reinforcement was to reduce the maximum stress-concentration factor to 2.60.

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