Finite Element Analysis and Fatigue Evaluation of the Threaded Marine Riser Connector

1988 ◽  
Vol 110 (2) ◽  
pp. 85-92 ◽  
Author(s):  
T. Sato ◽  
S. Sano ◽  
K. Ishikawa ◽  
T. Nakano
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
External Pressure ◽  
Axisymmetric Body ◽  
Large Contribution ◽  
Marine Riser ◽  
Element Analysis ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Fatigue Evaluation

Finite element analyses were conducted of the threaded marine riser connector which has the main, internal, and external shoulder seals. The objectives of the analyses are to evaluate the fatigue resistance, strength, and seal capability of the connector under the bending, tensile, internal and external pressure loads. An element which models the bending effect in an axisymmetric body is developed and implemented into the computer program ADINA. Using the program, stress concentration factors at the corner and threaded parts of the connector under these loads are obtained. The large contribution of both shoulders to the reduction of the stress concentration factors is found to be quite clear. The seal mechanism and the stress response of the connectors are also clarified. The fatigue evaluation based on ASME Boiler and Pressure Vessel Code, Sec. III, Rules for Construction of Nuclear Power Plant Components, Division 1, Subsection NB are compared with the experimental results.

Evaluation of Stress Concentration Factors by Finite Element Analysis

2006 ◽  
Author(s):  
Andrzej T. Strzelczyk ◽  
San S. Ho
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Automatic Generation ◽  
Published Data ◽  
Element Analysis ◽  
Direct Evaluation ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Fatigue Evaluation

In the ASME Code fatigue evaluation, the total stress at the critical region of a structure is often calculated as a product of nominal stress and the SCF (stress concentration factor). The SCF values are usually taken from technical material like the Welding Research Bulletin [1] or Peterson’s Stress Concentration Factors book [2]. However, the published data do not cover all stress concentration cases; furthermore, many results are ambiguous or with limited accuracy. This paper recommends direct evaluation of the stress concentration by finite element analysis. It presents examples of automatic generation of finite element models which apply to practical cases. The examples show that the finite element method is an effective way for stress concentration assessment; the method can give accurate (convergent) results for a wide variety of cases of geometry and loading conditions.

An Estimation Formula of the Stress Concentration Factor of the Butt-Welded Joint

2007 ◽  
Vol 353-358 ◽  
pp. 1995-1998
Author(s):  
Byeong Choon Goo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Gas Metal Arc Welding ◽  
Element Analysis ◽  
Butt Weld ◽  
Estimation Formula ◽  
Metal Arc Welding ◽  
Concentration Factors ◽  
Stress Concentration Factors

The purpose of this paper is to develop an estimation formula of stress concentration factors of butt-welded components under tensile loading. To investigate the influence of weld bead profiles on stress concentration factors of double V groove butt-welded joints, butt-welded specimens were made by CO2 gas metal arc welding. And the three main parameters, the toe radius, flank angle and bead height were measured by a profile measuring equipment. By using the measured data, the influence of three parameters on the stress concentration factors was investigated by a finite element analysis. It is shown that the three parameters have similar effects on the stress concentration factors. According to the simulation results, a formula to estimate the stress concentration factors of butt-weld welded structures was proposed and the estimated concentration factors from the formula were compared with the results obtained by the finite element analysis. The two results are in a good agreement.

Experimental, numerical and parametric studies on stress concentration factors of T-joints under tension

2021 ◽  
pp. 136943322110499
Author(s):  
Feleb Matti ◽  
Fidelis Mashiri
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Numerical Study ◽  
Hot Spot ◽  
Joint Models ◽  
Element Analysis ◽  
T Joints ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Good Agreement

This paper investigates the behaviour of square hollow section (SHS) T-joints under static axial tension for the determination of stress concentration factors (SCFs) at the hot spot locations. Five empty and corresponding concrete-filled SHS-SHS T-joint connections were tested experimentally and numerically. The experimental investigation was carried out by attaching strain gauges onto the SHS-SHS T-joint specimens. The numerical study was then conducted by developing three-dimensional finite element (FE) T-joint models using ABAQUS finite element analysis software for capturing the distribution of the SCFs at the hot spot locations. The results showed that there is a good agreement between the experimental and numerical SCFs. A series of formulae for the prediction of SCF in concrete-filled SHS T-joints under tension were proposed, and good agreement was achieved between the maximum SCFs in SHS T-joints calculated from FE T-joint models and those from the predicted formulae.

An Assessment of Structural Details in Lightweight Marine Structures

2004 ◽  
Author(s):  
Carlos A. Pereira ◽  
Paulo P. Silva ◽  
Anto´nio F. Mateus ◽  
Joel A. Witz
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Failure Modes ◽  
Marine Structures ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Structural Details ◽  
Concentration Factors ◽  
Stress Concentration Factors

This paper presents the results of investigations into the mechanics and failure modes of structural details usually encountered in lightweight marine structures. The structural analyses are performed using non-linear finite element analysis. The stress concentration factors and expected fatigue lives of the as designed and the as built structural details are evaluated and alternative configurations are discussed with the aim of improving the designs for production.

scholarly journals DETERMINATION OF STRESS CONCENTRATION FACTORS OF A STEAM TURBINE ROTOR USING FINITE ELEMENT ANALYSIS

1970 ◽  
Vol 40 (2) ◽  
pp. 137-141
Author(s):  
R. Nagendra Babu ◽  
K. V. Ramana ◽  
K. Mallikarjuna Rao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Steam Turbine ◽  
Turbine Rotor ◽  
Element Analysis ◽  
Steam Turbine Rotor ◽  
Fine Mesh ◽  
Concentration Factors ◽  
Stress Concentration Factors

Stress Concentration Factors are significant in machine design as it gives rise to localized stress when any change in the design of surface or abrupt change in the cross section occurs. Almost all machine components and structural members contain some form of geometrical or microstructural discontinuities. These discontinuities are very dangerous and lead to failure. So, it is very much essential to analyze the stress concentration factors for critical applications like Turbine Rotors. In this paper Finite Element Analysis (FEA) with extremely fine mesh in the vicinity of the blades of Steam Turbine Rotor is applied to determine stress concentration factors.Keywords: Stress Concentration Factors; FiniteElement Analysis; ANSYS.DOI: 10.3329/jme.v40i2.5355Journal of Mechanical Engineering, Vol. ME 40, No. 2, December 2009 137-141

The Effect of a Large Hole on the Stress Concentration Factor of a Satellite Hole in a Tension Field

1999 ◽  
Vol 121 (3) ◽  
pp. 252-256 ◽  
Author(s):  
C. S. Sloan ◽  
M. D. Cowell ◽  
T. F. Lehnhoff
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Hole Diameter ◽  
Element Analysis ◽  
Large Hole ◽  
Concentration Factors ◽  
Stress Concentration Factors

Stress concentration factors have been determined for large hole to small hole diameter ratios (D/d) of 10 to 50 for two holes in an infinitely wide tension-loaded panel. Finite element analysis was used to model the system of two holes in a plate that approximates the infinitely wide and tall case. Both the D/d ratio and edge to edge hole spacing were examined for hole placement along an axis perpendicular to the direction of the tension field. It was found for large D/d ratios that the stress concentration factor was only dependent on the distance between the hole edges divided by the large hole diameter. For the configurations analyzed, the stress concentration factors varied from approximately 3 to 11.

Bolt Head Fillet Stress Concentration Factors in Cylindrical Pressure Vessels

2001 ◽  
Vol 123 (3) ◽  
pp. 381-386 ◽  
Author(s):  
Gowri Srinivasan ◽  
Terry F. Lehnhoff
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Three Dimensional ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Three Dimensional Finite Element ◽  
Circle Diameter ◽  
Maximum Stresses

Linear three-dimensional finite element analysis (FEA) was performed on bolted pressure vessel joints to determine maximum stresses and stress concentration factors in the bolt head fillet as a result of the prying action. The three-dimensional finite element models consisted of a segment of the flanges containing one bolt, using cyclic symmetry boundary conditions. The flanges were each 20 mm in thickness with 901.7 mm inner diameter. The outer flange diameter was varied from 1021 to 1041 mm in steps of 5 mm. The bolt circle diameter was varied from 960.2 to 980.2 mm in steps of 5 mm. The bolts used were 16-mm-dia metric bolts with standard head and nut thickness. The threads were not modeled. The internal vessel pressure was 0.6895 MPa (100 psi). Stress concentration factors in the bolt head fillet were calculated, and they ranged from 3.34 to 4.80. The maximum stress in the bolt as well as the stress concentration factors in the bolt head fillet increase with an increase in bolt circle diameter for a given outer flange dimension. Keeping the bolt circle diameter constant, bolt stress and stress concentration factors in the bolt head fillet decrease with increase in outer flange diameter. The maximum stresses in the bolt were also calculated according to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code and the Verein Deutscher Ingenieur (VDI) guidelines and compared to the results observed through finite element analysis. The stresses obtained through FEA were larger than those predicted by the ASME and VDI methods by a factor that ranged between 2.96 to 3.41 (ASME) and 2.76 to 3.63 (VDI).

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