Mechanical Properties on the Welded Connection of Pipe and Hollow Spheres Joints

2011 ◽  
Vol 189-193 ◽  
pp. 3452-3457
Author(s):  
Ya Jie Yan ◽  
Hong Gang Lei ◽  
Xue Yang
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Wall Thickness ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Hollow Spheres ◽  
Steel Structures ◽  
Element Analysis ◽  
Static Tests

Taking pipe - hollow spherical node as the object, and using ANSYS finite element analysis software, established five kinds of finite element model to analyze the stress concentration at the weld connection of the different connections of steel structures - hollow ball under the uniaxial tension. Obtained this node’s stress concentration factor, stress distribution, by changing the hollow spherical diameter and wall thickness, pipe’s diameter and wall thickness, obtained the trend of the stress concentration factor under different control ball matches. Take static tests on typical structures of two specifications 6 hollow sphere nodes, get the measured stress concentration factor, and stress distribution of this node. Through comparative analysis of theoretical analysis and experimental results, show that the two rules are consistent. The research results can provide basis for improving the pipe - hollow spherical joints connecting structural.

Numerical Investigation of Stress Concentration Factor at Irregular Corrosion Pit Under Tension-Torsion Loading

2014 ◽  
Author(s):  
Yuhui Huang ◽  
Chengcheng Wang ◽  
Shan-Tung Tu ◽  
Fu-Zhen Xuan ◽  
Takamoto Itoh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Aspect Ratio ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Three Dimensional ◽  
Element Analysis ◽  
Stress Concentration Factors ◽  
Local Dissolution

Finite element analysis is adopted to study the stress concentration of pit area under tension-torsion loading. The stress concentration factors under regular evolution and irregular evolution of pits are investigated by conducting a series of three-dimensional semi-elliptical pitted models. Based on the finite element analysis, it can be concluded that pit aspect ratio (a/2c) is a significant parameter affecting stress concentration factor (SCF) for regular evolution pits. Pits, having higher aspect ratio, are very dangerous form and can cause significant reduction in the load carrying capacity. When local dissolution occurs in the pitting area, SCF will have a sharp increase, it is more probable for a crack to initiate from these areas compared with pits for regular evolution. Furthermore, local dissolution coefficient is proposed to study effect of local dissolution within the pit on SCF.

Theoretical Analysis and Experimental Verification of the Stress Concentration Factor at the Steel Tube-Welded Hollow Sphere Connection Node

2016 ◽  
Vol 851 ◽  
pp. 739-744
Author(s):  
Bo Li ◽  
Hong Gang Lei ◽  
Xu Yang
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Theoretical Analysis ◽  
Hollow Sphere ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Hot Spot ◽  
Steel Tube ◽  
Element Analysis ◽  
Hot Spot Stress

In this paper, the author uses ANSYS, the software of finite element analysis, to establish the finite element model, the hot spot stress value of different connection structures of steel tube-welded hollow sphere under uniaxial elongation has been analyzed, the theoretical stress concentration factor of this joint has been obtained. Through the static test on the four typical test-piece, 26 steel tube-welded hollow spherical nodes in total, the actually measured stress concentration factor of the joints has been obtained. The theoretical analysis basically coincides with the law of stress concentration factor obtained from the test results.

Finite Element Analysis on Stress Concentration of Well Casing With Corrosion Pits

2010 ◽  
Author(s):  
Jing Zhang ◽  
Jianchun Fan ◽  
Laibin Zhang ◽  
Dong Wen ◽  
Yumei Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Spherical Cavity ◽  
High Stress ◽  
Orifice Diameter ◽  
Element Analysis ◽  
Corrosion Pits

Corrosion-induced pits will disturb the original stress distribution of casing and appear local high stress area. Through 3-D finite element analysis on casing with spherical and cylindrical corrosion cavity, the stress concentration degree and the influences of cavity shape, size and orifice diameter on stress concentration factor are determined and analyzed. The results show that the depth and shape of corrosion cavities are major factors impacting the stress concentration factor. For the casing with corrosion pits, the smaller orifice diameter, the more obvious influence of hemisphere effect on stress concentration factor. With the transition from shallow-spherical cavity to exact hemispherical cavity or from exact hemispherical cavity to deep-spherical cavity or from exact hemispherical cavity to cylindrical cavity, the changes of stress concentration factor show different characteristics.

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.

scholarly journals A Study on the Stress Concentration Factor Induced in Double Countersunk Holes Due to Uniaxial Tension

2020 ◽  
Vol 25 (4) ◽  
pp. 59-68
Author(s):  
Mohammad A. Gharaibeh
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Response Surface ◽  
Uniaxial Tension ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Rectangular Plates ◽  
Least Squares Regression ◽  
Effective Equation ◽  
Element Analysis

AbstractFinite element and response surface methods were utilized to investigate the stress concentration factor induced in isotropic rectangular plates with two identical countersunk rivet holes due to uniaxial tension. In this investigation, the finite element model was constructed using ANSYS software and used to produce stress concentration factor (SCF) data. Additionally, the response surface method (RSM) was implemented to characterize the influence of the problem geometric parameters on the SCF. Besides, RSM combined with least squares regression methods were employed to formulate a simple and effective equation to mathematically compute the stress concentration factor (Kt) value. This equation was consequently verified with finite element analysis (FEA) results. Lastly, an optimum plate and holes configuration that minimizes the SCF was suggested and hence recommended.

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.

Numerical stress analysis for fatigue evaluation of welded tubular T-joints

1993 ◽  
Vol 20 (2) ◽  
pp. 269-286 ◽  
Author(s):  
D. I. Nwosu ◽  
A. S. J. Swamidas ◽  
K. Munaswamy
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Stress Concentration Factor ◽  
Bending Stress ◽  
Element Analysis ◽  
T Joints ◽  
Shell Finite Element ◽  
Good Agreement

The stress distribution along the intersection of offshore tubular T-joints under the action of axial and in-plane and out-of-plane (bending) brace loading has been investigated using degenerated shell elements. The ratios of through-thickness membrane to bending stress and bending to total stress have been obtained using a simple linear interpolation between the stresses on the inner and outer surfaces of the tube. The nominal brace stress and the maximum principal stress values have been used for stress concentration factor determination. The influence of thickness and other geometric parameters on the stress distribution along the intersection was investigated in two ways, viz., increasing the chord thickness while maintaining a constant brace thickness, and keeping the chord thickness constant while reducing the brace thickness.Comparison of the shell finite-element results obtained in this study with the semiloof thin-shell finite-element results of the University College, London (UCL), exhibits good agreement. Good agreement exists between the results of this study and the UCL parametric equations for the chord and the brace of the joint, with a maximum difference of about 7% on the braceside around the saddle position. Comparisons between the finite-element results and other known parametric equations for stress concentration factor with different diametral, wall thickness, and chord thickness and ratios also show good agreement. A comparison of the results obtained from the finite-element analysis and the experimental results of the Canadian Cooperative Fatigue Studies Program, carried out at Memorial University of Newfoundland and University of Waterloo, is also made. Key words: stress distribution, finite-element analysis, stress concentration factors, membrane stress, bending stress, tubular T-joints.

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