Finite Element Analysis on Dynamic Characteristics of Hybrid Bearing Spindle System

2011 ◽  
Vol 487 ◽  
pp. 505-509
Author(s):  
P. Guan ◽  
M. Li ◽  
B.C. Li ◽  
Tian Biao Yu ◽  
Wan Shan Wang
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Load Capacity ◽  
Element Model ◽  
Element Analysis ◽  
Spindle System ◽  
Oil Film ◽  
Hybrid Bearing ◽  
Stiffness And Damping ◽  
Film Stiffness

Due to having the features of high accuracy, high stiffness, high load capacity and longer service life, the hybrid bearing spindle system is widely used in grinding. This paper presents an analysis method of hybrid bearing spindle dynamic characteristics. The method uses CFD method to solve the oil film pressure field, instead of Reynolds equation, in order to obtain the oil film stiffness and damping. With the obtained oil film stiffness and damping to build the appropriate constraints, 3D finite element model of the hybrid bearing spindle system is established, and the modal analysis of the spindle system is carried out. Compared the analysis results with the theoretical calculation results, the feasibility and correction of the method are proved.

scholarly journals Response of the Flat Reinforced Concrete Floor Slab with Openings under Cyclic In-Plane Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Eden Shukri Kalib ◽  
Yohannes Werkina Shewalul
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Load Capacity ◽  
Element Model ◽  
Absorption Capacity ◽  
Hysteretic Behavior ◽  
Element Analysis ◽  
Floor Slab ◽  
Floor Slabs

The responses of flat reinforced concrete (RC) floor slabs with openings subjected to horizontal in-plane cyclic loads in addition to vertical service loads were investigated using nonlinear finite element analysis (FEA). A finite element model (FEM) was designed to perform a parametric analysis. The effects of opening sizes (7%, 14%, 25%, and 30% of the total area of the slab), opening shapes (elliptical, circular, L-shaped, T-shaped, cross, and rectangular), and location on the hysteretic behavior of the floor slab were considered. The research indicated that openings in RC floor slabs reduce the energy absorption capacity and stiffness of the floor slab. The inclusion of 30% opening on the floor slab causes a 68.5%, 47.3%, and 45.6% drop in lateral load capacity, stiffness, and lateral displacement, respectively, compared to the floor slab with no openings. The flat RC floor slab with a circular opening shape has increased efficiency. The placement of the openings is more desirable by positioning the openings at the intersection of two-column strips.

Finite Element Analysis for Static Behaviour of the CNC Turning Machine Spindle

2014 ◽  
Vol 555 ◽  
pp. 555-560 ◽  
Author(s):  
Doru Bardac ◽  
Constantin Dogariu
Keyword(s):  
Finite Element ◽  
Machine Tool ◽  
High Speed ◽  
High Performance ◽  
Element Model ◽  
Design Activity ◽  
Element Analysis ◽  
Spindle System ◽  
Machine Spindle ◽  
Main Spindle

This paper presents a method to investigate the characteristics of a turning high-speed spindle system. The geometric quality of high-precision parts is highly dependent on the performance of the entire machining system,especially by the main spindle behaviour. The machine tool main spindle units is focused on direct driven spindle units for high-speed and high performance cutting. This paper analyzes the static behavior for a turning machine spindle and presents some activities to improve the CAD model for such complex systems. The proposed models take into account the spindle with the detailed bearing system. The analysis was performed during the design activity and was based on Finite Elements Method. Starting from the 3D designed model, using FEM done by means of ANSYS analysis the structure stiffness was evaluated and, by consequence, the influence on the machine tool precision. The aim of this paper is to develop a finite element model of the machine spindle system and to use this method for design optimization. The 3D model was designed using the SolidWorks CAD software. The static analysis was completed by modal, harmonic response and thermal analysis, but their results will be presented in other papers.

Structural investigation of steel-reinforced epoxy granite machine tool column by finite element analysis

2019 ◽  
Vol 233 (11) ◽  
pp. 2267-2279 ◽  
Author(s):  
Prabhu Raja Venugopal ◽  
M Kalayarasan ◽  
PR Thyla ◽  
PV Mohanram ◽  
Mahendrakumar Nataraj ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cast Iron ◽  
Machine Tool ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Static Stiffness ◽  
Element Analysis ◽  
Static And Dynamic Characteristics ◽  
Machining Center

Higher damping with higher static stiffness is essential for improving the static and dynamic characteristics of machine tool structures. The structural vibration in conventional machine tools, which are generally made up of cast iron and cast steel, may lead to poor surface finish and the dimensional inaccuracy in the machined products. It leads to the investigation of alternative machine tool structural materials such as concrete, polymer concrete, and epoxy granite. Although epoxy granite has a better damping capacity, its structural stiffness (Young's modulus) is one-third as compared to cast iron. Therefore, the present work represents optimization of the structural design of the vertical machining center column by introducing various designs of steel reinforcement in the epoxy granite structure to improve its static and dynamic characteristics using experimental and numerical approaches. A finite element model of the existing cast iron vertical machining center column has been developed and validated against the experimental data obtained using modal analysis. Furthermore, finite element models for various epoxy granite column designs have been developed and compared with the static and dynamic characteristics of cast iron column. A total of nine design configurations for epoxy granite column with steel reinforcement are evolved and numerical investigations are carried out by finite element analysis. The proposed final configuration with standard steel sections has been modeled using finite element analysis for an equivalent static stiffness and natural frequencies of about 12–20% higher than cast iron structure. Therefore, the proposed finite element model of epoxy-granite-made vertical machining center column can be used as a viable alternative for the existing column in order to achieve higher structural damping, equivalent or higher static stiffness and, easy and environmental-friendly manufacturing process.

Static and dynamic behavior of steel-reinforced epoxy granite CNC lathe bed using finite element analysis

2020 ◽  
Vol 234 (4) ◽  
pp. 595-609
Author(s):  
Shanmugam Chinnuraj ◽  
PR Thyla ◽  
S Elango ◽  
Prabhu Raja Venugopal ◽  
PV Mohanram ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cast Iron ◽  
Machine Tool ◽  
Dynamic Characteristics ◽  
Torsional Rigidity ◽  
Element Model ◽  
Element Analysis ◽  
Cnc Lathe ◽  
Machine Tool Structures

Machine tools are used to manufacture components with desired size, shape, and surface finish. The accuracy of machining is influenced by stiffness, structural damping, and long-term dimensional stability of the machine tool structures. Components machined using such machines exhibit more dimensional variations because of the excessive vibration during machining at higher speeds. Compared to conventional materials like cast iron, stone-based polymer composites such as epoxy granite have been found to provide improved damping characteristics, by seven to ten folds, due to which they are being considered for machine tool structures as alternate materials. The stiffness of structures made of epoxy granite can be enhanced by reinforcing with structural steel. The current work highlights the design and analysis of different steel reinforcements in the lathe bed made of the epoxy granite composite to achieve equivalent stiffness to that of cast iron bed for improved static and dynamic performances of the CNC lathe. A finite element model of the existing the cast iron bed was developed to evaluate the static (torsional rigidity) and dynamic characteristics (natural frequency) and the results were validated using the experimental results. Then finite element models of five different steel reinforcement designs of the epoxy granite bed were developed, and their static and dynamic behaviors were compared with the cast iron bed through numerical simulation using finite element analysis. The proposed design (Design-5) of the epoxy granite bed is found to have an improvement in dynamic characteristics by 4–10% with improved stiffness and offers a mass reduction of 22% compared to the cast iron bed, hence it can be used for the manufacture of the CNC lathe bed and other machine tool structures for enhanced performance.

Research on the Static and Dynamic Characteristics of Misaligned Journal Bearing Considering the Turbulent and Thermohydrodynamic Effects

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Guohui Xu ◽  
Jian Zhou ◽  
Haipeng Geng ◽  
Mingjian Lu ◽  
Lihua Yang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Static And Dynamic Characteristics ◽  
Oil Film ◽  
Stiffness And Damping ◽  
Film Stiffness ◽  
Journal Misalignment ◽  
Oil Film Pressure

Journal misalignment usually exists in journal bearings that affect nearly all the bearings static and dynamic characteristics including minimum oil film thickness, maximum oil film pressure, maximum oil film temperature, oil film stiffness, and damping. The main point in this study is to provide a comprehensive analysis on the oil film pressure, oil film temperature, oil film thickness, load-carrying capacity, oil film stiffness, and damping of journal bearing with different misalignment ratios and appropriately considering the turbulent and thermo effects based on solving the generalized Reynolds equation and energy equation. The results indicate that the oil thermo effects have a significant effect on the lubrication of misaligned journal bearings under large eccentricity ratio. The turbulent will obviously affect the lubrication of misaligned journal bearings when the eccentricity or misalignment ratio is large. In the present design of the journal bearing, the load and speed become higher and higher, and the eccentricity and misalignment ratio are usually large in the operating conditions. Therefore, it is necessary to take the effects of journal misalignment, turbulent, and thermal effect into account in the design and analysis of journal bearings.

Research on the Dynamic Characteristics of NC Boring Machine Spindle System Based on Finite Element Analysis

2013 ◽  
Vol 819 ◽  
pp. 71-75
Author(s):  
Feng Jiao ◽  
Guang Ming Sun ◽  
Jian Hui Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Characteristics ◽  
Hydrodynamic Lubrication ◽  
Dynamic Stiffness ◽  
Element Analysis ◽  
Spindle System ◽  
Machine Performance ◽  
Machine Spindle ◽  
The Impact

In this paper, elastic hydrodynamic lubrication theory was introduced into bearing dynamic stiffness calculation process to take into account the impact of the oil film on the rolling stiffness. Dynamic characteristics of NC boring machine spindle system dedicated to the manufacturing of bearing retainer were studied based on finite element analysis software. The rationality of the structural design of spindle was verified in the paper. The research provided a theoretical basis for the improvement of machine performance and dynamic design of NC boring machine spindle.

Nonlinear Finite Element Analysis of the Bearing Capacity of a New Type of Column under Axial Load

2011 ◽  
Vol 255-260 ◽  
pp. 45-48 ◽  
Author(s):  
Ya Feng Xu ◽  
Xin Zhao ◽  
Yi Fu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Axial Load ◽  
Load Capacity ◽  
Element Model ◽  
Steel Tube ◽  
Element Analysis ◽  
Composite Columns ◽  
Steel Ratio

Based on experimental research, the bearing performance of the new column (steel tube-reinforced concrete composite columns combination strengthened with angle steel and CFRP) has been studied in detail by finite element method. A finite element model is established based on a series of assumption. The load-displacement curves are obtained. The influence of steel ratio and thickness of CFRP layers to the bearing capacity is analyzed too. The result shows that both the steel ratio and the thickness of CFRP layers have great contribution to the axial load capacity. The finite element analysis results and theoretical analysis which are in good agreement show that simulation results are generally right.

The Effects of Interbedded Friction on Load Capacity of Rhombic Wire Wound Vessel

2011 ◽  
Vol 221 ◽  
pp. 517-521
Author(s):  
Jun Fei Wu ◽  
Wei Gao ◽  
Xiao Chen Zhu
Keyword(s):  
Finite Element ◽  
Program Development ◽  
Load Capacity ◽  
Element Model ◽  
Parametric Modeling ◽  
Post Processing ◽  
Element Analysis ◽  
Whole Process ◽  
The Finite Element Analysis ◽  
The Finite Element Model

From the parametric modeling, the APDL tool can be used in ANSYS to build the finite element model of rhombic wire wound vessel. Only a small amount of parameters have to be input in order to accomplish the whole process of program development such as constructing model, meshing, creating contact pairs, bringing restrictions and loads to bear on vessels as well as solving and post-processing. It can be easy to use the developed batch program to achieve the finite element analysis of vessels and get the influence of interbedded friction on the load capacity of rhombic wire wound vessel under different working pressures.

scholarly journals Experimental and Numerical Investigation of Short-Term Behavior of Partially Precast and Partially Encased Composite Beams

2020 ◽  
Vol 28 (3) ◽  
pp. 29-39
Author(s):  
Liufeng Zhang ◽  
Yinghua Yang
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Peak Load ◽  
Element Model ◽  
Bending Test ◽  
Test Results ◽  
Short Term ◽  
Element Analysis ◽  
The Finite Element Model ◽  
Bending Response

AbstractIn this paper, the short-term behavior of a new partially pre-cast and partially encased composite (PPEC) beam is studied. This paper reports the results of a 4-point bending test on a full-scale PPEC beam and sets out the load displacement response, short-term stiffness, peak load capacity and failure mode of the proposed PPEC beam. In addition, a finite element analysis of the PPEC beam is carried out, and the numerical simulation results are compared with the test results. The results show that the finite element model can reflect the bending response of the PPEC beam. In this paper, three different calculation methods are used to compare the deflection of the PPEC beam. The results show that the values calculated by the bending-shear coupling method formula agree relatively well with the test results.

Vibration Modal Analysis of the Upper Frame of Hydraulic Excavator

2012 ◽  
Vol 605-607 ◽  
pp. 1203-1206
Author(s):  
Cui Peng Zuo ◽  
Yi Qi Zhou ◽  
Rui Huo ◽  
Li Wang ◽  
Hao Li
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Weak Links ◽  
Hydraulic Excavator ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Structure Improvement ◽  
Vibration Modal

As the upper frame is an essential supporting structure of Hydraulic Excavator, dynamic characteristics of the structure are particularly important. The finite element model of the upper frame is established by the finite element analysis software, and then modal analysis is carried out in absolute freeness. The former fifteen modes are adopted to review its inherent frequencies and vibration modes seriously, and the dynamic characteristics of the frame are clear. Analysis result indicates that there are some weak links in the structure, and suggestions of modification are put forward for the further structure improvement.

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