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 Stress Analysis and Experimental Research of Tubular Joints of Offshore Drilling Platform

1984 ◽  
Vol 106 (1) ◽  
pp. 43-45
Author(s):  
T. Y. Chen ◽  
B. Z. Chen ◽  
Y. Q. Wang
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Stress Analysis ◽  
Experimental Research ◽  
Stress Concentration Factor ◽  
Analytical Method ◽  
Concentration Factor ◽  
Offshore Drilling ◽  
Tubular Joints ◽  
Good Agreement

An analytical method for the stress analysis of tubular joints of T, Y, K type is presented in this paper. The stress distribution and stress concentration factor of the joints are calculated. Numerical results are in good agreement with the experimental results.

Pipe Joint Management for Risers and Pipelines

2021 ◽  
Author(s):  
Ghiath (Guy) Mansour
Keyword(s):  
Fatigue Strength ◽  
Stress Concentration ◽  
Software Development ◽  
Wall Thickness ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Joint Management ◽  
Pipe Joints ◽  
Best Fit ◽  
Pipe Joint

Abstract Minimizing the stress concentration factor (SCF) in pipe joint welding subjected to fatigue is a major concern. Machining the joint ends is one way to achieve this. However, this adds cost, time, risk of potential crack starters, and loss of wall thickness which is detrimental for fatigue, strength, and engineering criticality assessment (ECA) in particular. Pipe joint sorting (certain joints in sequence) and end matching (rotating the pipe joints for best fit) are other ways. However, this adds time, costly logistics, risk of errors, and does not guarantee the minimum possible SCF is achieved. In a typical project, more pipe joints are procured than required in order to mitigate contingencies. For pipelines, this overage is typically a percentage of the required number of joints or pipeline length. For risers, typically double the required number of joints is procured where half of the joints is sent offshore for installation and the remaining half is kept onshore for a spare riser. Then, it becomes very important to send for installation the best pipe joints that produce the best (lowest) SCFs out of the entire batch of pipe joints. This requires calculating the SCF for every potential match of any random joints to be welded together, and then choosing the best joints. Performing such calculations by spreadsheet is not feasible considering the tremendous number of required iterations and calculations. A pipe joint management software development is presented herein which accomplishes this task and examples provided to illustrate the benefits. Note: Selecting pipe joints with the best end measurements, whether ID, OD, OOR, or thickness does not guarantee that the minimum possible SCFs will be achieved since the SCF is a function of all those measurements.

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.

Experimental studies to determine strain concentration factors for space tubular joints

1987 ◽  
Vol 22 (4) ◽  
pp. 237-245 ◽  
Author(s):  
R Sundaravadivelu ◽  
C G Nandakumar ◽  
S K Srivastava ◽  
C Ganapathy
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Experimental Studies ◽  
Offshore Structures ◽  
Strain Concentration ◽  
Tubular Joints ◽  
Orthogonal Plane ◽  
Concentration Factors ◽  
Semi Empirical

This paper presents studies carried out on grouted and ungrouted space tubular joints, with K in one plane and T in the orthogonal plane. Three models have been tested for different load cases adopting T, K, and both T and K (STK) configurations. The tubular joints used in offshore structures, especially in jacket platforms, are multiplanar and some are grouted and hence their study is essential. The stress concentration factor, SCF, as determined using the semi-empirical formulae which are applicable for planar joints are not appropriate for space, grouted joints. The results of the present study indicates that the SCF as determined by formulae for simple joints is unsafe in the plane of K and conservative in the plane of T for the space joint. The effect of the grout is to reduce the stress concentration.

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.

scholarly journals Stress Concentration Factor of A Two-Planar Double KT Tubular Joint due to In-Plane Bending Loading in Steel Offshore Structures

2018 ◽  
Vol 177 ◽  
pp. 01006
Author(s):  
Prastianto Rudi Walujo ◽  
Hadiwidodo Yoyok Setyo ◽  
Fuadi Ibnu Fasyin
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Element Model ◽  
Offshore Structures ◽  
Geometrical Parameters ◽  
Offshore Structure ◽  
Wide Range ◽  
Tubular Joint

The purpose of this study is to investigate the proper Stress Concentration Factor (SCF) of a 60° two-planar DKT tubular joint of a tripod wellhead offshore structure. So far, calculation of SCF for a multi-plane tubular joint was based on the formulation for the simple/uniplanar tubular joints that yield in over/under prediction of the SCF of the joint. This situation in turn decreasing the accuracy of fatigue life prediction of the structures. The SCF is one of the most important parameters in the tubular joint fatigue analysis. The tubular joint is modelled as finite element models with bending loads acting on the braces that cover a wide range of dimensionless geometrical parameters (β, τ, γ). The effect of such parameters on the SCF distribution along the weld toe of braces and chord on the joint are investigated. Validation of the finite element model has shown good agreement to the global structural analysis results. The results of parametric studies show that the peak SCF mostly occurs at around crown 2 point of the outer central brace. The increase of the β leads to decrease the SCF. While the increase of the τ and γ leads to increase the SCF. The effect of parameter β and γ on the SCF are greater than the effect of parameter τ.

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