Study on Cavitation and Tribological of TiO2 Nano-Film on Bearing Pads Surface

2021 ◽  
Vol 21 (12) ◽  
pp. 5906-5911
Author(s):  
Juan Zhang ◽  
Donghui Li ◽  
Bo Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Protective Layer ◽  
Front Surface ◽  
Vital Role ◽  
Stable Operation ◽  
Discretization Method ◽  
Element Analysis

Bearings play a vital role in the operation of a two-axis system. Long-term bearing use inevitably produce bubbles and frictional damage. Therefore, the protection of bearings is critical for the stable operation of a two-axis system. In this study, a TiO2 nanofilm is used to physically protect a bearing. The discretization method is used to analyse the cavitation process. Cavitation primarily occurs on the front surface of the pad during bearing operation. A finite element analysis of a bearing pad coated and not coated with TiO2 nanofilms shows that TiO2 nanofilms can effectively absorb the cavitation force exerted on pads, thereby reducing inflicted damage. Moreover, the TiO2 nanofilm reduces the friction coefficient of the pad surface, promoting good bearing capacity of the bearing during rotation. The TiO2 nanofilm serves as a protective layer that improves the anti-wear and bearing performance of a two-axis system.

3D Coupled Thermomechanical Finite Element Analysis of Ultrasonic Consolidation

2007 ◽  
Vol 539-543 ◽  
pp. 2651-2656 ◽  
Author(s):  
C.J. Huang ◽  
E. Ghassemieh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Stress Field ◽  
Ultrasonic Wave ◽  
Ultrasonic Vibration ◽  
Softening Effect ◽  
Element Analysis ◽  
Consolidation Process ◽  
Ultrasonic Consolidation

A 3-D coupled temperature-displacement finite element analysis is performed to study an ultrasonic consolidation process. Results show that ultrasonic wave is effective in causing deformation in aluminum foils. Ultrasonic vibration leads to an oscillating stress field. The oscillation of stress in substrate lags behind the ultrasonic vibration by about 0.1 cycle of ultrasonic wave. The upper foil, which is in contact with the substrate, has the most severe deformation. The substrate undergoes little deformation. Apparent material softening by ultrasonic wave, which is of great concern for decades, is successfully simulated. The higher the friction coefficient, the more obvious the apparent material softening effect.

Study on Wrinkles during Rotary-Draw Bending Forming

2019 ◽  
Vol 943 ◽  
pp. 43-47
Author(s):  
Xia Zhu ◽  
Keiji Ogi ◽  
Nagatoshi Okabe
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
General Purpose ◽  
Straight Tube ◽  
Tube Material ◽  
Rotary Draw Bending ◽  
Element Analysis ◽  
Draw Bending ◽  
Wrinkle Generation

The purpose of this research is to determine the state inside the material using finite-element analysis and to improve the performance of a rotary-draw bending forming by clarifying the mechanism of wrinkle generation. An analytical model of rotational drawing was made by using the general-purpose nonlinear finite-element analysis software MSC Marc, and the analytical results were compared with experimental results to verify the validity of the model. Furthermore, the mechanism of wrinkle generation was investigated. With the progress of processing, wrinkles occur not in the R part but in the original tube-side straight-tube part. The coefficient of friction between the tube material and the R portion of the bending mold promotes the occurrence of wrinkles and the growth of the generated wrinkles. Because wrinkles occur even if the friction coefficient between the tube material and bending mold R part is ignored, the generation condition of wrinkles also depends on parameters other than the friction coefficient.

scholarly journals Long-Term Performance of Trestle Bridges: Case Study of an Indonesian Marine Port Structure

2020 ◽  
Vol 8 (5) ◽  
pp. 358 ◽  
Author(s):  
Yusak Oktavianus ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Gideon Kusuma ◽  
Colin Duffield
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Service Life ◽  
Field Measurement ◽  
Field Measurements ◽  
Element Analysis ◽  
Moment Capacity ◽  
Non Destructive

A precast reinforced concrete (RC) T-beam located in seaport Terminal Peti Kemas (TPS) Surabaya built in 1984 is used as a case study to test the accuracy of non-destructive test techniques against more traditional bridge evaluation tools. This bridge is mainly used to connect the berth in Lamong gulf and the port in Java Island for the logistic purposes. The bridge was retrofitted 26 years into its life by adding two strips of carbon fiber reinforced polymer (CFRP) due to excessive cracks observed in the beams. Non-destructive field measurements were compared against a detailed finite element analysis of the structure to predict the performance of the girder in terms of deflection and moment capacity before and after the retrofitting work. The analysis was also used to predict the long-term deflections of the structure due to creep, crack distribution, and the ultimate moment capacity of the individual girder. Moreover, the finite element analysis was used to predict the deflection behavior of the overall bridge due to vehicle loading. Good agreement was obtained between the field measurement and the analytical study. A new service life of the structure considering the corrosion and new vehicle demand is carried out based on field measurement using non-destructive testing. Not only are the specific results beneficial for the Indonesian port authority as the stakeholder to manage this structure, but the approach detailed also paves the way for more efficient evaluation of bridges more generally over their service life.

Research on the Effects of Friction Coefficient on Three-Point Bending by Finite Element Analysis

2015 ◽  
Vol 12 (12) ◽  
pp. 5139-5143
Author(s):  
Xiangguo Zhai ◽  
Fu Zhang ◽  
Hongwei Zhao ◽  
Cong Li ◽  
Zhaoxin Xu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Element Analysis ◽  
Three Point Bending

Sheet Metals Forming Die Design Using Finite Element Analysis and the Taguchi Method

2014 ◽  
Vol 621 ◽  
pp. 195-201
Author(s):  
Surangsee Dechjarern ◽  
Maitri Kamonrattanapisut
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Taguchi Method ◽  
Finite Element Model ◽  
Sheet Metal ◽  
Element Model ◽  
Die Design ◽  
Forming Process ◽  
Element Analysis

Sheet metal deep-draw die is primarily constructed with draw bead, which is then modified based on trial and error to obtain a successful forming without splitting. This work aims at a robust design of forming die using numerical analysis and the Taguchi method. A three dimensional elastoplastic finite element model of a sheet metal forming process of SPCEN steel has been successfully developed using the material flow stress obtained from the modified Erichsen cup test. The model was validated with the actual forming experiment and the results agreed well. The influence of draw bead parameters on splitting and thinning distributions were examined using the Taguchi method. Four parameters, namely the friction coefficient, draw bead height, radius and shoulder radius were investigated. The Taguchi main effect analysis and ANOVA results show that the height and shoulder radius of the draw bead are the most important factor influencing the thinning distribution. Applying the Taguchi method and using the minimum thinning percentage as the design criteria, the optimum die design was identified as height, radius, shoulder radius and the friction coefficient of 4, 8, 8 mm and 0.125 respectively. The verified finite element model using the optimum die design was conducted. The predicted Taguchi response was within 5.9% from finite element analysis prediction. The improvement in the reduction of thinning percentage was 22.35%.

A study on finite element analysis for simplification of curvature extrusion method

2018 ◽  
Vol 32 (19) ◽  
pp. 1840043
Author(s):  
J. O. Yu ◽  
Y. H. Kim ◽  
Nagamachi Takuo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Extrusion Process ◽  
Experimental Results ◽  
Element Analysis ◽  
Extrusion Method ◽  
Good Agreement

To eliminate the complexity of curvature extrusion process, a new extrusion method was proposed. In this study, a finite element analysis for curvature extrusion was studied to commercialize this extrusion method that creates curvature in a tilting method. When simulating an extrusion process, it is important to fix the appropriate friction coefficient and fillet value to avoid peel-out problems such that the finite element disappears. Therefore, the actual extrusion results and the simulated results were compared to find conditions that the element would not disappear. There was a good agreement between the simulation and experimental results when the coefficient friction was 0.4 and the fillet was 0.4 mm.

Finite Element Analysis in Orthopaedics

1987 ◽  
Vol 110 ◽  
Author(s):  
James B. Koeneman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Beam Theory ◽  
Stress Distributions ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Bone Changes ◽  
Joint Implants ◽  
Bone Structures

AbstractPredicting the stress state in bones is important to the understanding of bone remodeling and the long-term reliability of total joint implants. Beam theory, 2-D and 3-D finite element analysis have been used to calculate stress distributions. These finite element analyses of bone structures are progressing from crude models for which the clinical relevance has been questioned to an important tool which is necessary to understand stress related bone changes.

Finite Element Analysis of the Rolling-Sliding Contact of Vibrationally Loaded Bearings Based on a Micro Friction Model

2013 ◽  
Vol 768-769 ◽  
pp. 714-722 ◽  
Author(s):  
Andreas Konrad ◽  
Wolfgang Nierlich ◽  
Jürgen Gegner
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Residual Stresses ◽  
Equivalent Stress ◽  
Rolling Contact ◽  
Sliding Contact ◽  
Element Analysis ◽  
Fem Model ◽  
Mixed Friction

Mixed friction acting in a rolling contact increases the v. Mises equivalent stress and shifts the maximum towards the surface. Tangential stresses are superimposed to the stress distribution. The resulting position of the maximum v. Mises stress depends on the magnitude of the friction coefficient and is located directly on the surface from values of about 0.25 upwards. The impact of three-dimensional machine vibrations on rolling bearings in operation can cause severe mixed friction running conditions. Residual stress distributions measured on indentation-free raceways indicate high friction coefficients of up to greater than 0.25. The surfaces reveal smoothing of the finishing structure but no adhesive wear. The simulation of the vibrationally loaded rolling-sliding contact is based on the tribological model of localized friction coefficient. This approach avoids seizing by allowing for increased friction only in intermittently changing subareas of the contact at low sliding speed. The macroscopic friction coefficient, meeting a mixing rule, does not exceed 0.1. The finite element method (FEM) is used for the stress analysis. In the first step, a simplified FEM model involves a circumferentially oriented band of high friction coefficient from 0.2 to 0.5 within a cylindrical roller contact. The resulting depth distributions of the v. Mises equivalent stress during overrolling and the corresponding residual stresses are evaluated below the inner ring raceway of the bearing. The features of the FEM model are discussed in detail. The increased sliding friction in the band shifts the maximum of the v. Mises equivalent stress to the surface. Compressive residual stresses are induced in the edge zone. Depending on the applied Hertzian pressure, an additional subsurface peak occurs. First results of the finite element analysis are presented.

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