Effect of Geometry of Grooves on Connection Strength of Hydraulically Expanded Tube-to-Tubesheet Joints

2005 ◽  
Vol 127 (4) ◽  
pp. 430-435 ◽  
Author(s):  
H. F. Wang ◽  
Z. F. Sang
Keyword(s):  
Groove Depth ◽  
Geometrical Factor ◽  
Geometrical Parameters ◽  
Connection Strength ◽  
Design And Manufacturing ◽  
Average Residual ◽  
Calculation Results ◽  
Stress And Deformation ◽  
Axisymmetrical Model ◽  
Residual Stress And Deformation

The object of this paper is to investigate the effect of the geometry of circumferential grooves on the connection strength of hydraulically expanded tube-to-tubesheet joints of heat exchangers. Seven-tube models with different groove widths, depths, spacings, and locations were fabricated under the same expansion pressure by commercial hydraulic expanders. Then the corresponding pullout forces were gained by experimental means. In addition, the process of hydraulic expansion of tube-to-tubesheet joints was simulated using the nonlinear finite element method based on a two-dimensional (2D) axisymmetrical model. The residual stress and deformation of joints were determined, and the effect of geometrical parameters of the grooves on the connection strength of joints was studied in terms of the average residual contact pressure of the joints. The experimental and calculation results indicate that the most important geometrical factor for determining the connection strength is the groove width. Groove depth, spacing, and location have a secondary effect. Optimum geometrical sizes of grooves are proposed based on maximum axial strength. These can provide a reference for the revision of design and manufacturing codes.

Effect of the Geometry of Groove on Connection Strength of the Hydraulically Expanded Tube-to-Tubesheet Joints of Heat Exchangers

2004 ◽  
Author(s):  
H. F. Wang ◽  
Z. F. Sang ◽  
G. E. O. Widera
Keyword(s):  
Heat Exchangers ◽  
Groove Depth ◽  
Groove Width ◽  
Geometrical Factor ◽  
Geometrical Parameters ◽  
Connection Strength ◽  
Average Residual ◽  
Calculation Results ◽  
Stress And Deformation ◽  
Axisymmetrical Model

The object of this paper is to investigate the effect of geometry of a groove on the connection strength of hydraulically expanded tube-to-tubesheet joints of heat exchangers. Seven-tube models with different groove width, depth, spacing and location were fabricated under the same expansion pressure by commercial hydraulic expanders. Then the corresponding pullout forces were gained by experimental means. In addition, the process of hydraulic expansion of tube-to-tubesheet joints was simulated using the nonlinear finite element method based on a 2-D axisymmetrical model. The residual stress and deformation of joints were determined, and the effect of geometrical parameters of the grooves on the connection strength of joints was studied in terms of the average residual contact pressure of the joints. The experimental and calculation results indicate that the most important geometrical factor for determining the connection strength is the groove width. Groove depth, spacing and location have a secondary effect. Optimum geometrical sizes of grooves are proposed based on maximum axial strength. These can provide a reference for the revision of design and manufacturing codes.

Numerical Simulation for Residual Stress and Deformation of Surface Welding on Membrane Water-Wall

2014 ◽  
Vol 490-491 ◽  
pp. 594-599
Author(s):  
Fan Ling Meng ◽  
Ai Guo Liu
Keyword(s):  
Residual Stress ◽  
Great Influence ◽  
Residual Deformation ◽  
Welding Residual Stress ◽  
Finite Element Software ◽  
Welding Sequence ◽  
Surface Welding ◽  
Stress And Deformation ◽  
Welding Sequences ◽  
Residual Stress And Deformation

Automatic MIG was adopted to weld Inconel 625 alloy on 20 G Membrane Waterwall, which can improve the capacities of high temperature corrosion resistance and wear resistance. To study the influence of Membrane Waterwall surface welding sequences on residual stress and residual deformation, this paper utilized finite element software ABAQUS and segmented moving heat source model to simulate the sequence welding, balanced welding from the middle to sides, balanced welding from sides to the middle, balanced skip welding from middle to sides and balanced skip welding from sides to the middle and studied their residual stresses and deformations. The simulation results indicated that there was a great influence of welding sequences on the residual stress and deformation. The optimal welding sequence was balanced skip welding from middle to sides and balanced skip welding from sides to the middle, which could change the stress distribution, decrease the welding residual stress by 17%, realize the even deformation of the whole welding section and decrease the bending deformation by 50%.

On the Optimum Groove Geometry for Herringbone Grooved Journal Bearings

2006 ◽  
Vol 128 (3) ◽  
pp. 585-593 ◽  
Author(s):  
A. M. Gad ◽  
M. M. Nemat-Alla ◽  
A. A. Khalil ◽  
A. M. Nasr
Keyword(s):  
Groove Depth ◽  
Radial Force ◽  
Journal Bearings ◽  
Friction Torque ◽  
Performance Characteristics ◽  
Width Ratio ◽  
Geometrical Parameters ◽  
Thrust Bearings ◽  
Circular Groove ◽  
Groove Profile

Recently, herringbone-grooved journal bearings have had important applications in miniature rotating machines. The scribed grooves, on either the rotating or stationary member of the bearing, can pump the lubricant inward, which generates supporting stiffness and improves the dynamic stability, especially for concentric operation. Most of the previous investigations that dealt with herringbone grooved journal bearings and grooved thrust bearings were theoretical. Few experimental attempts for the investigation of the performance characteristics of herringbone grooved journal bearings (HGJBs) and grooved thrust bearings have been done. All these investigations concentrated on rectangular and circular groove profiles of HGJBs. In order to improve the performance characteristics of HGJBs, a new design of the groove profile, the beveled-step groove profile, is introduced. The introduced groove profile is capable of increasing the pressure recovery at the divergence of the flow over the step. In addition, it increases the amount of oil pumped inward over the circular groove profile. Optimization processes were carried out experimentally, in order to obtain the optimal geometry of the introduced groove profile. The optimum geometrical parameters of the groove (groove angle α, groove width ratio β, and groove depth ratio Γ) are 29deg, 0.5, and 2.0, respectively, which give maximum radial force and maximum radial stiffness of the beveled-step HGJB. In order to check the effectiveness of the introduced beveled-step groove profile, the obtained results were compared with that for rectangular groove profile. The comparison shows that the introduced beveled-step HGJBs have higher radial force, higher load carrying capacity, and lower friction torque than the rectangular HGJBs.

scholarly journals INFLUENCE OF CREEP CONCRETE ON SPACE STABILITY THIN-WALLED DOME COVERINGS

2021 ◽  
Vol 1 (24) ◽  
Author(s):  
Ekaterina Prokshits ◽  
Sergey Gridnev ◽  
Olga Sotnikova ◽  
Iana Zolotukhina
Keyword(s):  
Theory Of Elasticity ◽  
Deformation Condition ◽  
Software Systems ◽  
Geometrical Parameters ◽  
Loss Of Stability ◽  
Construction Mechanics ◽  
Body Construction ◽  
Calculation Results ◽  
Load Action ◽  
Thin Walled

The task was set, due to the capabilities of modern software systems, to assess the effect of the increase in inelastic deformations under prolonged load action on the loss of stability of thin-walled dome coverings. The study of the dependences of the forms of the loss of stability of dome covering from creep concrete that will help further with optimization calculations when determining of the most influencing parameters of designs. Calculation results of thin-walled concrete dome roof of circular outline under the influence of operational loadings with use of two modern program complexes are given in article. It is investigated intense and deformation condition of dome coverings as a part of construction from position of forecasting of possible forms of loss of stability, with use of opportunities of the final and element «MidasCivil» computer system. In work provisions of the theory of elasticity, mechanics of deformation of solid body, construction mechanics and also methods of mathematical modeling based on application of finite element method are used. The received results give the chance to rationally select geometrical parameters and material of design and also to set structural strength safety factors at the solution of problems of stability of different covers taking into account possible creep of material.

CHARACTERIZATION AND ANALYSES ON RESIDUAL STRESS AND DEFORMATION DISTRIBUTION IN LINE HEAT PROCESS

2021 ◽  
Vol 158 (A4) ◽  
Author(s):  
B Zhou ◽  
X Han ◽  
W Guo ◽  
Z Liu ◽  
S-K Tan
Keyword(s):  
Residual Deformation ◽  
Element Model ◽  
Heating Process ◽  
Stress Distributions ◽  
Forming Process ◽  
Line Heating ◽  
Bending Process ◽  
Stress And Deformation ◽  
The Impact ◽  
Residual Stress And Deformation

Line heating is an important plate bending process that has been adopted in shipyards for more than 60 years. This paper presents the results of a numerical and experimental study on the residual deformation and stress distribution in the plate forming process using the line heating method. In this paper, a finite element model was used to simulate the heating process, and the model was validated using experimental results. The model was then used to analyze the deformation and stress distributions in the heating and non-heating region. The impact of line heating and sequence of heating on both sides of a steel plate was discussed. The findings of the study show that the compression stress generated help to increase the shrinkage of line heating process. This study presents a valuable reference for similar thermal process.

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