A Study of a Non-API Flange

2017 ◽  
Author(s):  
Shah Alam ◽  
Ulan Dakeev
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Pressure ◽  
Oil And Gas ◽  
Band Width ◽  
Element Analysis ◽  
Acceptance Criterion ◽  
Elastic Plastic ◽  
Section Viii ◽  
Leak Tightness

API rated flanges [1] are used in oil and gas industries frequently. The current practice is to select a flange and its seal/gasket from a tabulated range of load and area of application. Some applications may require a unique flange or seal for a pressure and temperature that is not listed on the table. To design such non-API flange (geometry such as thickness, number of bolts, bolts pattern, etc. are different from API flange) that meets system requirements is a challenge. Currently there is no standard available as per authors knowledge to design non-API flange. Therefore, in this study, a finite element analysis with new acceptance criterion for the 5”-15-ksi non-API flange connection for different pressure and temperature has been performed. Elastic-plastic finite element analysis method is used to check the leak tightness [2]. A fatigue calculation based on elastic-plastic analysis with twice yield method as per ASME Section VIII, Division 2 [3], sec. 5.5.4, has also been performed. A new acceptance criterion based on industry practices are used for leak tightness. The contact pressure and contact pressure band width are used to check the leak tightness. The results showed that for all load cases seals have enough contact pressure and contact pressure band width to prevent leakage and they meet the acceptance criteria. The calculated fatigue life was found more than the required life for an application.

Finite Element Analysis of Repeated Indentation of an Elastic-Plastic Layered Medium by a Rigid Sphere, Part I: Surface Results

1995 ◽  
Vol 62 (1) ◽  
pp. 20-28 ◽  
Author(s):  
E. R. Kral ◽  
K. Komvopoulos ◽  
D. B. Bogy
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Half Space ◽  
Contact Pressure ◽  
Peak Load ◽  
Rigid Sphere ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Surface Stresses ◽  
Residual Displacements

A comprehensive elastic-plastic finite element analysis is presented for the axisym-metric problem of a frictionless rigid sphere indenting a half-space with a harder and stiffer layer. The indenter is modeled by contact elements, thereby avoiding a priori assumptions for the pressure profile. Two layer thicknesses are examined, with layer elastic modulus and yield stress both two and four times greater than those of the substrate. Perfectly plastic and isotropic strain-hardening behavior of the layer and substrate media are investigated. At least three complete load-unload cycles are applied to a peak load of 300 times the load necessary to initiate yielding in a half-space of the substrate material. The effect of hardening properties on the loaded and residual stresses is presented and the consequences for crack initiation at the surface are discussed. Results for the contact pressure and surface stresses and deformations are presented, and the influence of residual displacements and load cycles on the contact pressure and the loaded and residual surface stresses is investigated.

Elastic-Shakedown Analysis of Axisymmetric Nozzles

2003 ◽  
Vol 125 (4) ◽  
pp. 365-370 ◽  
Author(s):  
Martin Muscat ◽  
Donald Mackenzie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Lower Bound ◽  
Pressure Vessel ◽  
Element Analysis ◽  
Shakedown Analysis ◽  
Elastic Plastic ◽  
Section Viii ◽  
Elastic Shakedown ◽  
Division 2

An investigation of the shakedown behavior of axisymmetric nozzles under internal pressure is presented. The analysis is based on elastic-plastic finite element analysis and Melan’s lower bound shakedown theorem. Calculated shakedown pressures are compared with values from the literature and with the ASME Boiler and Pressure Vessel Code Section VIII Division 2 primary plus secondary stress limits. Results obtained by the lower bound method are also verified by cyclic elastic-plastic finite element analysis.

Elastic and elastic-plastic finite element analysis of hollow tubes with axisymmetric internal projections under combined axial and pressure loading

2001 ◽  
Vol 36 (4) ◽  
pp. 373-390 ◽  
Author(s):  
S. J Hardy ◽  
M. K Pipelzadeh ◽  
A. R Gowhari-Anaraki
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Plastic Material ◽  
Axial Loading ◽  
Material Model ◽  
Pressure Loading ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Applied Loading

This paper discusses the behaviour of hollow tubes with axisymmetric internal projections subjected to combined axial and internal pressure loading. Predictions from an extensive elastic and elastic-plastic finite element analysis are presented for a typical geometry and a range of loading combinations, using a simplified bilinear elastic-perfectly plastic material model. The axial loading case, previously analysed, is extended to cover the additional effect of internal pressure. All the predicted stress and strain data are found to depend on the applied loading conditions. The results are normalized with respect to material properties and can therefore be applied to geometrically similar components made from other materials, which can be represented by the same material models.

scholarly journals Effect of coronal plane acetabular correction on joint contact pressure in Periacetabular osteotomy: a finite-element analysis

2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Kenji Kitamura ◽  
Masanori Fujii ◽  
Miho Iwamoto ◽  
Satoshi Ikemura ◽  
Satoshi Hamai ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Pressure ◽  
Periacetabular Osteotomy ◽  
Anterior Wall ◽  
Coronal Plane ◽  
Patient Specific ◽  
Element Analysis ◽  
Joint Contact ◽  
Joint Contact Pressure

Abstract Background The ideal acetabular position for optimizing hip joint biomechanics in periacetabular osteotomy (PAO) remains unclear. We aimed to determine the relationship between acetabular correction in the coronal plane and joint contact pressure (CP) and identify morphological factors associated with residual abnormal CP after correction. Methods Using CT images from 44 patients with hip dysplasia, we performed three patterns of virtual PAOs on patient-specific 3D hip models; the acetabulum was rotated laterally to the lateral center-edge angles (LCEA) of 30°, 35°, and 40°. Finite-element analysis was used to calculate the CP of the acetabular cartilage during a single-leg stance. Results Coronal correction to the LCEA of 30° decreased the median maximum CP 0.5-fold compared to preoperatively (p <  0.001). Additional correction to the LCEA of 40° further decreased CP in 15 hips (34%) but conversely increased CP in 29 hips (66%). The increase in CP was associated with greater preoperative extrusion index (p = 0.030) and roundness index (p = 0.038). Overall, virtual PAO failed to normalize CP in 11 hips (25%), and a small anterior wall index (p = 0.049) and a large roundness index (p = 0.003) were associated with residual abnormal CP. Conclusions The degree of acetabular correction in the coronal plane where CP is minimized varied among patients. Coronal plane correction alone failed to normalize CP in 25% of patients in this study. In patients with an anterior acetabular deficiency (anterior wall index < 0.21) and an aspherical femoral head (roundness index > 53.2%), coronal plane correction alone may not normalize CP. Further studies are needed to clarify the effectiveness of multiplanar correction, including in the sagittal and axial planes, in optimizing the hip joint’s contact mechanics.

The Finite Element Analysis of Plate's Distance on Push-Extend Multi-under-Reamed Pile

2012 ◽  
Vol 468-471 ◽  
pp. 2517-2520 ◽  
Author(s):  
Xin Ying Xie ◽  
Xin Sheng Yin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Element Analysis ◽  
Elastic Plastic ◽  
The Finite Element Analysis ◽  
Plastic Theory

In this paper ,it analyses the push-extend multi-under-reamed pile in use of elastic-plastic theory by the software ANSYS.It takes four push-extend multi-under-reamed piles which are the same except plates' distance.It introduces the realative theory to make the anlysis much more accuracy.The results which is taken by ANSYS are researched to find out the regularity and can certain the reasonable plate's distance to anlyze the bearing capacity of push-extend multi-under-reamed pile at the same time.

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