Behavior of NPS30 Pipe Subject to Denting Load

2014 ◽  
Author(s):  
Hossein Ghaednia ◽  
Kyle Gerard ◽  
Sudip Bhattacharjee ◽  
Sreekanta Das
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Petroleum Products ◽  
Lateral Loads ◽  
Element Analysis ◽  
Engineering Research ◽  
Three Dimensional Finite Element

Pipeline is the common mode for transporting oil, gas, and various petroleum products. Structural integrity of oil and gas transmission pipelines is often threatened by external interferences such as concentrated lateral loads and as a result, a failure of the pipeline may occur due to “mechanical damages”. Sometime, this load may not cause immediate rupture of pipes; rather form a dent which can reduce the pressure capacity of the pipeline. A dent is a localized defect in the pipe wall in the form of a permanent inward plastic deformation. This kind of defect is a matter of serious concern for the pipeline operator since a rupture or a leak may occur. Accordingly, an extensive experimental study is currently underway at the Centre for Engineering Research in Pipelines (CERP), University of Windsor on 30 inch (762 mm) diameter and X70 grade pipes with D/t of 90. The aim of this research is to examine the influence of various parameters such as dent shape and service pressure on strain distributions of dented pipe. Also, three-dimensional finite element models were developed and validated for determining strains underneath the indenter. The load-deformation behavior of pipes subject to this type of lateral denting load obtained from experimental study and finite element analysis is discussed in this paper. In addition, distributions of important strains in and around the dent obtained from the study are also discussed.

A Three-Dimensional Finite Element Analysis of Restored Deciduous Canine

2015 ◽  
Vol 638 ◽  
pp. 123-129 ◽  
Author(s):  
Florin Baciu ◽  
Claudia Bratosin ◽  
Aurelia Rusu-Casandra
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Bone Structure ◽  
Three Dimensional ◽  
Medical Problem ◽  
Ct Scanner ◽  
Chronic Infections ◽  
Element Analysis ◽  
Tooth Structure ◽  
Three Dimensional Finite Element

The literature reports that dental cavities are an international public health challenge and treatment of decays especially for young children is a medical problem of great importance. Early childhood caries progress rapidly and can cause functional, physical and dentofacial aesthetic impairment. Recent studies show that caries lesions can compromise children’s quality of life due to the pain and discomfort which could lead to disfigurement, acute and chronic infections and to alteration of meals and sleeping habits. Tooth decay occurs when acids in the mouth dissolve the outer layers of the tooth, stripping the tooth of important minerals. Because dental decay often goes untreated, the cavity grows and more tooth structure is lost. Restorative dentistry has the main purpose of rehabilitating the function and aesthetic of tooth. The structural integrity of the restored teeth depends on the state of stress in their different regions due to occlusal loads. The aim of this study performed with the finite element method is to evaluate the stress and strain distributions in bone structure-primary canine-restorative material assembly when a load of 120N is applied all over the upper surface of the model. Particular attention was given to an accurate computer reconstruction of the canine. Therefore with the aid of a CT scanner the tomography images obtained were processed with a special software (Mimics). Two dental restorative materials, commonly used in practice were chosen for the analysis and the results acquired are compared. Also the contact pressure at the interface bone-deciduous canine and deciduous canine-dental material is evaluated in both cases.

Use of Finite Element Analysis for Stud Pre-Tension Determination of Large Diameter Integral Flanges With Ring Joint Gaskets

2010 ◽  
Author(s):  
Upali Panapitiya ◽  
Haoyu Wang ◽  
Syed Jafri ◽  
Paul Jukes
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Oil And Gas ◽  
Large Diameter ◽  
Three Dimensional ◽  
Oil And Gas Industry ◽  
Element Analysis ◽  
Axial Forces ◽  
Three Dimensional Finite Element

Large diameter integral steel flanges are widely used in many applications in the oil and gas industry. The flanges of nominal pipe sizes, 26-inch and above with ring-joint gaskets as specified in ASME B 16.47 Standard, are used in the offshore applications for the transportation of oil and gas from production facilities. These pipelines require flanged connections at end terminations, mid-line tie-ins and expansion loops. The conventional design of large diameter steel flanges is based on one-dimensional analytical methods similar to the procedure in ASME VIII Boiler and Pressure Vessel Code, Division 1 Appendix 2. The effects of axial forces and bending moments are approximated by calculating an equivalent pressure. This usually results in conservative designs for the large flanges because it estimates the required stud pre-tension based on the assumption that the gasket will be unloaded entirely to a minimum stress, whereas only a small section of the gasket is subjected to low stress. This technical paper presents the quasi-static, nonlinear, and three-dimensional finite element models of large diameter steel flanged joint for the determination of stud pre-tension and change of stud tension under various loading conditions. The finite element analysis results are compared with the results obtained by using the equivalent pressure method and flange “Joint Diagram”.

scholarly journals Three-dimensional finite element analysis of the behaviour of cross passage between cast-iron tunnels

2016 ◽  
Vol 53 (6) ◽  
pp. 930-945 ◽  
Author(s):  
Zili Li ◽  
Kenichi Soga ◽  
Peter Wright
Keyword(s):  
Finite Element ◽  
Cast Iron ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Element Analysis ◽  
Soil Stiffness ◽  
Soil Loading ◽  
London Underground ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The behaviour of cast-iron cross passages in the London Underground was investigated using three-dimensional finite element models. Unlike the behaviour of a full tunnel ring, the structural integrity of a tunnel cross-passage opening relies on support from adjacent linings. In clayey soils, the opening may deform further as the soil stiffness changes from undrained to drained conditions. Degradation of the circumferential bolts and trackbed may also lead to further tunnel movement. A parametric study was conducted to examine the influence of soil stiffness and structural components (e.g., bolts and lintel) on the structural integrity of a tunnel opening. Results show that a lintel effectively transfers the load above the opening to the adjacent linings, and its distortion affects tunnel deformation significantly. If a lintel is not present, both bolts and friction between tunnel segments provide shear resistance to the lining deformation at the tunnel opening against soil loading. Results are compared with field observations made at a critical cross passage in one of the London Underground tunnels. The findings contributed to identifying the critical deformation mechanisms of cast-iron tunnel cross passages, which can be useful during inspection of such structures.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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