Reliability Study of the Hydraulically Expanded Tube-to-Tubesheet Joint

2005 ◽  
Vol 128 (3) ◽  
pp. 408-413 ◽  
Author(s):  
Caifu Qian ◽  
Chenghong Duan ◽  
Hongjie Yu ◽  
Hongwei Duan ◽  
Junli Tian
Keyword(s):  
Finite Element ◽  
Contact Surface ◽  
Three Dimensional ◽  
Element Model ◽  
Tube Sheet ◽  
Reliability Study ◽  
Pull Out ◽  
Finite Element Calculations ◽  
Grooved Tube ◽  
Contact Pressures

A three-dimensional parametrized finite element model is established for the nonlinear analysis of the hydraulically expanded tube-to-tubesheet joint. Distribution of the residual contact pressure on the contact surface between the tube and the tubesheet is investigated. It is found that sealing circular bands exist on the contact surface which enhance the sealing of the joint since the residual contact pressures on the sealing circular bands are higher than on other positions. The sealing circular bands are located close to the two ends of the hole when it is not grooved, but they are located at the two brinks of the groove for a grooved hole and in the latter case, the residual contact pressures are even higher, reflecting that the joint with a grooved tube-sheet hole is more capable of sealing. Experiments and finite element calculations for the pull-out force of the joint are also performed for different expansion pressures and groove widths. Results show that with the increase of the groove width, the measured pull-out force increases significantly and becomes larger and larger than the calculated one, which is owing to the scratch on the contact surface between the tube and tubesheet.

Comparisons of contact pressures of crowned rollers

2000 ◽  
Vol 214 (2) ◽  
pp. 147-156 ◽  
Author(s):  
S. H. Ju ◽  
T. L. Horng ◽  
K. C. Cha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Contact Surface ◽  
Three Dimensional ◽  
Accurate Analysis ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Contact Pressures

The present work determines the contact pressure and stress concentration between the crowned roller and the raceway by using three-dimensional finite element analysis. A number of crowned profiles with various dimensions were examined. Fine meshes and node-to-Hermit-surface contact elements were used along the contact surface in order to obtain accurate analysis results. A table was generated to show the stress concentration near the roller edge for various crowned profiles and dimensions. This table indicates that the exponential profile is the optimal crowned profile to eliminate stress concentration.

Strength and Fatigue Analysis of Tube-Sheet Subjected to Thermal Shock

2016 ◽  
Author(s):  
Jun Shen ◽  
Yanfang Tang ◽  
Juncheng Xu ◽  
Yinghua Liu
Keyword(s):  
Finite Element ◽  
Thermal Shock ◽  
Three Dimensional ◽  
Element Model ◽  
Calculation Model ◽  
Stress Profile ◽  
Tube Sheet ◽  
Mechanical Coupling ◽  
Time Points ◽  
Three Dimensional Finite Element

A calculation model for a tube-sheet under thermal shock loading with the finite element code ANSYS is established in this paper. A three-dimensional finite element model is established to simulate thermal shock process in order to obtain temperature and stress distributions of the structure. The duration time of the thermal shock is taken as about ten seconds and thermal cycling numbers are more than 1000 times for the whole service life of the structure. In order to capture accurate temperature and stress profile of this structure, thermo-mechanical coupling approach and transient thermal analysis is used. Temperature and stress distribution are obtained under the given thermal boundary conditions at different time points and it is also easy to get the stress amplitude of the other points in this structure between any two time points. According to the numerical results, the stress induced by thermal shock changes with time and its magnitude and amplitude cannot be ignored. Strength and fatigue evaluations are also performed according to ASME VIII-2 to ensure its safety.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

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.

scholarly journals Comparison of Tooth- and Bone-Borne Appliances on the Stress Distributions and Displacement Patterns in the Facial Skeleton in Surgically Assisted Rapid Maxillary Expansion—A Finite Element Analysis (FEA) Study

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1152
Author(s):  
Rafał Nowak ◽  
Anna Olejnik ◽  
Hanna Gerber ◽  
Roman Frątczak ◽  
Ewa Zawiślak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Rapid Maxillary Expansion ◽  
Stress Distributions ◽  
Maxillary Expansion ◽  
Facial Skeleton ◽  
Element Analysis ◽  
Maxillary Constriction

The aim of this study was to compare the reduced stresses according to Huber’s hypothesis and the displacement pattern in the region of the facial skeleton using a tooth- or bone-borne appliance in surgically assisted rapid maxillary expansion (SARME). In the current literature, the lack of updated reports about biomechanical effects in bone-borne appliances used in SARME is noticeable. Finite element analysis (FEA) was used for this study. Six facial skeleton models were created, five with various variants of osteotomy and one without osteotomy. Two different appliances for maxillary expansion were used for each model. The three-dimensional (3D) model of the facial skeleton was created on the basis of spiral computed tomography (CT) scans of a 32-year-old patient with maxillary constriction. The finite element model was built using ANSYS 15.0 software, in which the computations were carried out. Stress distributions and displacement values along the 3D axes were found for each osteotomy variant with the expansion of the tooth- and the bone-borne devices at a level of 0.5 mm. The investigation showed that in the case of a full osteotomy of the maxilla, as described by Bell and Epker in 1976, the method of fixing the appliance for maxillary expansion had no impact on the distribution of the reduced stresses according to Huber’s hypothesis in the facial skeleton. In the case of the bone-borne appliance, the load on the teeth, which may lead to periodontal and orthodontic complications, was eliminated. In the case of a full osteotomy of the maxilla, displacements in the buccolingual direction for all the variables of the bone-borne appliance were slightly bigger than for the tooth-borne appliance.

scholarly journals Experimental & FEM Analysis of Orthodontic Mini-Implant Design on Primary Stability

2021 ◽  
Vol 11 (12) ◽  
pp. 5461
Author(s):  
Elmedin Mešić ◽  
Enis Muratović ◽  
Lejla Redžepagić-Vražalica ◽  
Nedim Pervan ◽  
Adis J. Muminović ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Primary Stability ◽  
Fem Analysis ◽  
Implant Design ◽  
Special Focus ◽  
Engineering System ◽  
Mini Implants ◽  
Pull Out ◽  
Computer Aided

The main objective of this research is to establish a connection between orthodontic mini-implant design, pull-out force and primary stability by comparing two commercial mini-implants or temporary anchorage devices, Tomas®-pin and Perfect Anchor. Mini-implant geometric analysis and quantification of bone characteristics are performed, whereupon experimental in vitro pull-out test is conducted. With the use of the CATIA (Computer Aided Three-dimensional Interactive Application) CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing)/CAE (Computer Aided Engineering) system, 3D (Three-dimensional) geometric models of mini-implants and bone segments are created. Afterwards, those same models are imported into Abaqus software, where finite element models are generated with a special focus on material properties, boundary conditions and interactions. FEM (Finite Element Method) analysis is used to simulate the pull-out test. Then, the results of the structural analysis are compared with the experimental results. The FEM analysis results contain information about maximum stresses on implant–bone system caused due to the pull-out force. It is determined that the core diameter of a screw thread and conicity are the main factors of the mini-implant design that have a direct impact on primary stability. Additionally, stresses generated on the Tomas®-pin model are lower than stresses on Perfect Anchor, even though Tomas®-pin endures greater pull-out forces, the implant system with implemented Tomas®-pin still represents a more stressed system due to the uniform distribution of stresses with bigger values.

Reduction of Free-Edge Stress Concentration

1985 ◽  
Vol 52 (4) ◽  
pp. 801-805 ◽  
Author(s):  
P. R. Heyliger ◽  
J. N. Reddy
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Free Edge ◽  
Shear Stresses ◽  
Normal Stresses ◽  
Interlaminar Shear ◽  
Three Dimensional Elasticity

A quasi-three dimensional elasticity formulation and associated finite element model for the stress analysis of symmetric laminates with free-edge cap reinforcement are described. Numerical results are presented to show the effect of the reinforcement on the reduction of free-edge stresses. It is observed that the interlaminar normal stresses are reduced considerably more than the interlaminar shear stresses due to the free-edge reinforcement.

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