Tilting Pad Journal Bearing Misalignment Effect on Thermally Induced Synchronous Instability (Morton Effect)

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Dongil Shin ◽  
Alan B. Palazzolo
Keyword(s):  
Journal Bearing ◽  
Three Dimensional ◽  
Element Model ◽  
Fluid Film ◽  
Design Parameters ◽  
Radial Clearance ◽  
Thermally Induced ◽  
Morton Effect ◽  
Three Dimensional Finite Element ◽  
Journal Misalignment

Abstract This paper investigates the influence of misaligned journal bearing effects on the thermally induced rotor instability (Morton effect “ME”) problem. The Morton effect is caused by uneven viscous heating of the journal in a fluid film bearing, which causes thermal bending, especially in rotors with an overhung disc or coupling weight. The thermally induced bending in the shaft may cause a vibration instability, which results in an excessive level of synchronous vibration. Previous research focused on parametric studies of the rotor and bearing design parameters, including overhung mass, bearing radial clearance, and lubricant viscosity. The present study investigates the influence of journal misalignment on the Morton effect. A coupled fluid-thermal-structural, three-dimensional finite element model (FEM) is developed to simulate fluid film pressures and temperatures, and shaft temperatures and vibrations. Simulations were conducted with different ratios of journal misalignment, and different pad-pivot types to determine their effect on the phenomenon. The simulation results indicate that the amplitude of the misalignment angle affects the instability speed range (ISR) caused by the Morton effect under certain conditions.

Thermal Analysis and Optimization Design on Spindle Bearing of GSCK200A CNC Lathe

2011 ◽  
Vol 314-316 ◽  
pp. 1760-1763
Author(s):  
Le Ping Liu ◽  
Guo Hong Deng
Keyword(s):  
High Speed ◽  
Thermal Deformation ◽  
Optimization Design ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Clearance ◽  
Spindle Bearing ◽  
Heat Transfer Theory ◽  
Cnc Lathe ◽  
Three Dimensional Finite Element

Establish the three-dimensional finite element model of GSCK200A type High-speed & high-precision CNC Lathe spindle bearing, based on tribology and heat transfer theory, using ANSYS to analyze the corresponding temperature field and thermal deformation of spindle bearing in steady working state, according to this thermal deformation to obtain decrease volume of radial clearance, and the installation clearance optimization scheme is putted forward.

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 Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

Process Modeling in Laser Deposition of Multilayer SS410 Steel

2007 ◽  
Vol 129 (6) ◽  
pp. 1028-1034 ◽  
Author(s):  
Liang Wang ◽  
Sergio Felicelli
Keyword(s):  
Phase Transformation ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Element Model ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Dimensional Finite Element ◽  
Net Shaping ◽  
Three Dimensional Finite Element ◽  
Continuous Cooling Transformation Diagram

A three-dimensional finite element model was developed to predict the temperature distribution and phase transformation in deposited stainless steel 410 (SS410) during the Laser Engineered Net Shaping (LENS™) rapid fabrication process. The development of the model was carried out using the SYSWELD software package. The model calculates the evolution of temperature in the part during the fabrication of a SS410 plate. The metallurgical transformations are taken into account using the temperature-dependent material properties and the continuous cooling transformation diagram. The ferritic and martensitic transformation as well as austenitization and tempering of martensite are considered. The influence of processing parameters such as laser power and traverse speed on the phase transformation and the consequent hardness are analyzed. The potential presence of porosity due to lack of fusion is also discussed. The results show that the temperature distribution, the microstructure, and hardness in the final part depend significantly on the processing parameters.

Mechanical Simulation of Knee Movement in Basketball Shooting

2013 ◽  
Vol 336-338 ◽  
pp. 760-763
Author(s):  
Hui Yue
Keyword(s):  
Finite Element ◽  
Cruciate Ligament ◽  
Three Dimensional ◽  
Element Model ◽  
Basketball Player ◽  
Knee Movement ◽  
Dimensional Finite Element ◽  
Anterior Cruciate ◽  
Three Dimensional Finite Element

A short explanation of the finite element method as a powerful tool for mathematical modeling is provided, and an application using constitutive modeling of the behavior of ligaments is introduced. Few possible explanations of the role of water in ligament function are extracted from two dimensional finite element models of a classical ligament. The modeling is extended to a three dimensional finite element model for the human anterior cruciate ligament. Simulation of ligament force in pitching motion of basketball player is studied in this paper.

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