scholarly journals Finite Element Analysis of Ball Burnishing on Ball-End Milled Surfaces Considering Their Original Topology and Residual Stress

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 638 ◽  
Author(s):  
Cyrus Amini ◽  
Ramón Jerez-Mesa ◽  
J. Antonio Travieso-Rodriguez ◽  
Jordi Llumà ◽  
Aida Estevez-Urra
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Coefficient Of Friction ◽  
Surface Integrity ◽  
Finite Element Models ◽  
Real Surface ◽  
Ball Burnishing ◽  
Surface Geometry ◽  
Topological Features ◽  
The Coefficient Of Friction

Ball burnishing is a superfinishing operation whose objective is the enhancement of surface integrity of previously machined surfaces, hence its appropriateness to complement chip removal processes at the end of a production line. As a complex process involving plastic deformation, friction and three-dimensional interaction between solids, numerical solutions and finite element models have typically included a considerable amount of simplifications that represent the process partially. The aim of this paper is to develop a 3D numerical finite element model of the ball burnishing process including in the target workpiece real surface integrity descriptors resulting from a ball-end milled AISI 1038 surface. Specifically, its periodical topological features are used to generate the surface geometry and the residual stress tensor measured on a real workpiece is embedded in the target surface. Secondly, different models varying the effect of the coefficient of friction and the direction of application of burnishing passes with regards to the original milling direction are calculated. Results show that the resulting topology and residual stresses are independent of the burnishing direction. However, it is evident that the model outputs are highly influenced by the value of the coefficient of friction. A value of 0.15 should be implemented in order to obtain representative results through finite element models.

Asymptotic Stress Fields for Complete Contact Between Dissimilar Materials

2018 ◽  
Vol 86 (1) ◽  
Author(s):  
Kisik Hong ◽  
M. D. Thouless ◽  
Wei Lu ◽  
J. R. Barber
Keyword(s):  
Finite Element ◽  
Coefficient Of Friction ◽  
Dissimilar Materials ◽  
The Other ◽  
Stress Fields ◽  
Finite Element Models ◽  
Local Stresses ◽  
The Coefficient Of Friction ◽  
Complete Contact ◽  
Insight Into

We investigate the influence of material dissimilarity on the traction fields at the corners of a contact between an elastic right-angle wedge and an elastic half-plane. The local asymptotic fields are characterized in terms of the properties of the leading eigenvalue for cases of slip and stick as a function of the Dundurs bimaterial parameters α and β, and the coefficient of friction f. Permissible values of α and β are partitioned into two possible ranges, one where behavior is qualitatively similar to the case where the indenting wedge is rigid [α = 1] and the other where behavior is similar to the case where the materials are the same [α = β = 0]. The results give insight into the high local stresses at the edge of a contact between elastically dissimilar bodies and can also be used to evaluate the effectiveness of mesh refinement in corresponding finite element models.

Simulating Torsional Slip in V-Band Clamp Joints

2015 ◽  
Vol 798 ◽  
pp. 53-58
Author(s):  
Salahaddin M. Sahboun ◽  
Simon M. Barrans
Keyword(s):  
Finite Element ◽  
Coefficient Of Friction ◽  
Load Capacity ◽  
Contact Region ◽  
Finite Element Technique ◽  
Torsional Load ◽  
V Band ◽  
The Coefficient Of Friction ◽  
Element Technique

In this paper a finite element technique to predict the torsional load capacity of V-band clamp joints is presented. The development of this complex, multi-step analysis is explained and the results compared with alternate theories which ignore or take account of transverse friction in the band to flange contact region. It is shown that accounting for transverse friction yields a better comparison with the finite element results for lower coefficients of friction whilst ignoring this component gives better results for higher coefficients of friction. Torsional load capacity is shown to increase with band diameter and T-bolt tension but to be less dependent on the coefficient of friction.

Testing the Validity of Greenwood and Tripp’s Sum Surface Assumption for Elastic-Plastic Contact

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Ashutosh Roy ◽  
Bhargava Sista ◽  
Kumar Vemaganti
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Correlation Length ◽  
Coefficient Of Friction ◽  
Rough Surfaces ◽  
Surface Model ◽  
Finite Element Models ◽  
Rigid Plane ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

Abstract The complexity of modeling friction between rough surfaces has prompted many researchers to use Greenwood and Tripp’s sum surface assumption to simplify the analysis. This assumption approximates the contact between two rough surfaces as contact between their equivalent sum surface and a rigid plane. In this work, we develop detailed finite element models to test the sum surface assumption for surfaces with Gaussian and exponential autocorrelation functions. We consider surfaces with differing surface roughness and correlation length values. For each case, we conduct simulations of two rough surfaces interacting in compression followed by shear, and a corresponding equivalent surface model based on the sum surface assumption. Multiple realizations of each parameter combination are simulated to obtain a statistical picture of the responses. We find that (a) the sum surface assumption consistently under-predicts the static coefficient of friction and (b) the equivalent surface model is less accurate for surfaces with differing correlation length-to-surface roughness ratios.

Research of Reinforce Stress on the Pressure Structure of Submersible Vehicle

2014 ◽  
Vol 496-500 ◽  
pp. 590-593
Author(s):  
Guan Nan Chu ◽  
Qing Yong Zhang ◽  
Guo Chun Lu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Hoop Stress ◽  
External Pressure ◽  
Finite Element Models ◽  
Cylinder Pressure ◽  
Simulation Experiments ◽  
Element Analysis ◽  
Load Carrying

In order to improve the load-carrying properties of pressure structure, a new method to improve the external bearing limit is put forward and residual stress is used. Based on finite element analysis, finite element models of cylinder pressure structure of submersible vehicle are established to produce hoop residual stress in the process of outward expansion. According to a lot of data of simulation experiments, the result indicates that hoop residual stress is compressive on the outer surface of the pipe and the hoop stress keeps tensile on the inside surface. This kind of stress distribution is helpful to the cylinder structure and can improve its bearing capacity of external pressure. Moreover, the rules of the residual stress are got. The influences of physical dimension, yield strength of material and the expansion rate to the stress distribution are analyzed. The measures to produce the stress distribution are also presented.

Deformation Characteristics of Ultra-Fine Grained Al6061 Chip in Machining by Finite Element Method

2010 ◽  
Vol 44-47 ◽  
pp. 2931-2934
Author(s):  
Chun Ling Wu ◽  
Bang Yan Ye
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Coefficient Of Friction ◽  
Metal Cutting ◽  
High Hardness ◽  
Rake Angle ◽  
Fine Grained ◽  
The Coefficient Of Friction ◽  
Cutting Velocity ◽  
Element Method

Ultra-fine grained chips with higher hardness and strength than bulk can be produced by severe plastic deformation during orthogonal metal cutting. A finite element method was developed to characterize the distribution of stress, strain, strain rate and temperature in the deformation area at different rake angles and cutting velocities. The coefficient of friction in the tool-chip interface is approximately obtained according model of mean coefficient of friction which is based on experiments in any machining conditions. The formation mechanics of ultra-fine grained chip is discussed and effect of rake angle on microstructure of chips is highlighted. The results of experiment and modeling have shown that chip materials with ultra-fine grained and high hardness can be produced with more negative tool rake angle at some lower cutting velocity.

scholarly journals A Contact Characteristic of Roller Bearing with Palm Oil-based Grease Lubrication

2021 ◽  
Vol 89 (2) ◽  
pp. 139-149
Author(s):  
Yap Jun Heng ◽  
Nurul Farhana Mohd Yusof ◽  
Lee Ann Yen ◽  
Shazlina Abd Hamid ◽  
Nurul Nadzirah Mohd Yusof
Keyword(s):  
Finite Element ◽  
Coefficient Of Friction ◽  
Palm Oil ◽  
Frictional Contact ◽  
Roller Bearing ◽  
Rolling Contact ◽  
Von Mises Stress ◽  
The Coefficient Of Friction ◽  
Contact Characteristic ◽  
Von Mises

Grease lubricants are widely used in rolling contact applications to reduce friction between two rolling surfaces. Improper lubrication may cause high contact stress and deformation to the bearings and lead to machine failure The purpose of this study is to investigate the coefficient of friction produced by newly developed palm oil-based grease and to investigate the contact characteristics in lubricated roller bearings. In this work, the coefficient of friction of new greases was evaluated experimentally and the values were compared with the conventional mineral oil-based grease to investigate the friction performance. The friction test was performed using a four-ball tester. The finite element model was developed based on the roller bearing geometry and the simulation was carried out the evaluate the contact characteristic. The experimental result shows that the palm oil grease formulation A had the least coefficient of friction, followed by palm oil grease formulation B, mineral grease and food grade grease. This indicates that palm oil-based grease has the potential to be applied in rolling contact applications due to low friction characteristics. Finite element analysis shows that the maximum von Mises stress and total deformation for frictional contact are higher than the frictionless contact. For the frictional contact analysis with various lubricant COF, similar values were obtained with von Mises stress at 400.69 MPa and 3.4033×10-4 mm deformation. The finding shows that the small difference in grease COF did not affect the rolling contact. The finding also shows that the newly developed biodegradable grease has a similar performance in terms of rolling contact friction and contact characteristic in a condition that the bearing is operating in normal condition.

Finite element analysis of fretting wear considering variable coefficient of friction

2018 ◽  
Vol 233 (5) ◽  
pp. 758-768 ◽  
Author(s):  
Ling Li ◽  
Le Kang ◽  
Shiyun Ma ◽  
Zhiqiang Li ◽  
Xiaoguang Ruan ◽  
...  
Keyword(s):  
Finite Element ◽  
Coefficient Of Friction ◽  
Variable Coefficient ◽  
Friction Model ◽  
Slip Condition ◽  
Fretting Wear ◽  
Partial Slip ◽  
Wear Volume ◽  
The Coefficient Of Friction ◽  
Contact Surfaces

Fretting wear is a kind of material damage in contact surfaces caused by microrelative displacement between two bodies. It can change the profile of contact surfaces, resulting in loosening of fasteners or fatigue cracks. Finite element method is an effective method to simulate the evolution of fretting wear process. In most studies of fretting wear, the coefficient of friction was assumed to be constant to simplify model and reduce the difficulty of solving. However, fretting wear test showed that the coefficient of friction was a variable related to the number of fretting cycles. Therefore, this paper introduces the coefficient of friction as a function of the number of fretting cycles in numerical simulation. A wear model considering variable coefficient of friction is established by combining energy consumption model and adaptive grid technique. The nodes of contact surfaces are updated through the UMESHMOTION subroutine. The effects of constant coefficient of friction and variable coefficient of friction on fretting wear are analyzed by comparing the wear amount under different loading conditions. The results show that when compared with coefficient of friction model, fretting wear is obviously affected by variable coefficient of friction and the variable coefficient of friction model has a larger wear volume when the fretting is in partial slip condition and mixed slip condition. In gross slip condition, the difference of wear volume between variable coefficient of friction model and coefficient of friction model decreases with the increase in the displacement amplitudes.

scholarly journals Finite Element Modelling of Laser Stitch Welding Joints for Structural Dynamic Predictions

2019 ◽  
Vol 16 (2) ◽  
pp. 6556-6567
Author(s):  
M. A. S. Aziz Shah ◽  
M. A. Yunus ◽  
M. N. Abdul Rani ◽  
M. S. Mohd Zin ◽  
W. I. I. Wan Iskandar Mirza
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Dynamic Behaviour ◽  
Welding Process ◽  
Shell Element ◽  
High Strength ◽  
Mode Shapes ◽  
Finite Element Models ◽  
Structural Dynamic ◽  
Welded Structure

Laser stitch welding is a joining technique that has been increasingly popular in automotive industries, such as in the manufacturing and assembling of the car’s body-in-white (BiW) due to its advantages over the resistance spot weld, such as low heat application and high strength weld. The dynamic behaviour of a laser stitch welded structure is relatively difficult to predict accurately due to local parameters being induced during the laser welding process, such as heat affected zone (HAZ) and residual stress in the welded structure. This paper presents the idea of modelling the laser stitch weld by investigating different types of element connectors that can be used to represent laser stitch weld, such as rigid body element (RBE2), shell element (CQUAD4), bar element (CBAR) and area contact model (ACM2) format of element connectors. The accuracy of finite element models of laser stitch welded joints is compared in terms of natural frequencies and mode shapes with the experiment counterparts. The dynamic behaviour of the measured structure is obtained by using an impact hammer with free-free boundary conditions. It is found that the accuracy of the finite element models of the laser stitch welded structure highly depends on the involvement of residual stress and the heat affected zones that are generated from the welding process.

scholarly journals Finite Element Analysis of Surface Integrity in Deep Ball-Burnishing of a Biodegradable AZ31B Mg Alloy

Metals ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 136 ◽  
Author(s):  
Mohammad Uddin ◽  
Colin Hall ◽  
Ryan Hooper ◽  
Eric Charrault ◽  
Peter Murphy ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Integrity ◽  
Mg Alloy ◽  
Ball Burnishing ◽  
Element Analysis
Sign in / Sign up

Export Citation Format

Share Document