scholarly journals Determining Friction and Flow Stress of Material during Forging

2021 ◽  
Author(s):  
Uday Shanker Dixit ◽  
Vikash Kumar ◽  
Pavel Petrov ◽  
Boris Saprykin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Flow Stress ◽  
Coefficient Of Friction ◽  
Empirical Relation ◽  
Cold Forging ◽  
Coulomb’S Coefficient Of Friction ◽  
Forging Load ◽  
Inverse Procedure ◽  
Element Method

Determination of flow stress and friction in cold forging is of paramount importance. In this work, an inverse procedure is developed for predicting the Coulomb’s coefficient of friction and strain-dependent flow stress simultaneously based on the measurement of bulge and forging load. It is also established that in cold forging Coulomb’s coefficient of friction can be approximated as half the friction factor in Tresca (or constant friction) model. In the inverse procedure, forging load is estimated analytically but bulging is estimated by developing an empirical relation. The efficacy of the inverse procedure is ascertained by the data obtained from finite element method simulations. Finite element method was implemented in ABAQUS and validated with the results available in literature. In most of the cases, inverse procedure provides less than 5% error in the estimates of friction and flow stress. A sensitivity analysis is also carried out to study the effect of measurement error. It is observed that error in the estimation of friction is proportional to error in the measurement of bulge. The novelty of the method lies in the quickness and simplicity of the method.

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.

Application of FEM and Abductive Network to Determine Forging Force and Billet Dimensions of Near Net-Shape Helical Bevel Gear Forging

2018 ◽  
Vol 920 ◽  
pp. 205-210
Author(s):  
Tung Sheng Yang ◽  
Yu Liang Chang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Process Parameters ◽  
Prediction Models ◽  
Bevel Gear ◽  
Near Net Shape ◽  
Abductive Network ◽  
Forging Force ◽  
Forging Load ◽  
Element Method

In this paper, the use of the finite element method in conjunction with abductive network is presented to predict the maximum forging force and the volume of billet during near net-shape helical bevel gear forging. The maximum forging load and volume of billet are influenced by the process parameters such as modules, number of teeth, and die temperature. A finite element method is used to investigate the forging of helical bevel gear. In order to verify the prediction of FEM simulation for forging load, the experimental data are compared with the results of current simulation. A finite element analysis is also utilized to investigate the process parameters on forging load and volume of billet. Additionally, the abductive network was applied to synthesize the data sets obtained from the numerical simulation. The prediction models are then established for the maximum forging load and volume of billet of near net-shape helical bevel gear forging under a suitable range of process parameters. After the predictions of the maximum forging force and the volume of billet, the optimum of the power of forging machine and the dimensions of billet are determined.

scholarly journals Analysis on Aircraft Brake Squeal Problem Based on Finite Element Method

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ming Zhang ◽  
Ran Xu ◽  
Hong Nie
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Coefficient Of Friction ◽  
Mode Analysis ◽  
Brake Squeal ◽  
Force Fluctuation ◽  
Viscoelastic Damping Material ◽  
Brake Force ◽  
Unstable Vibration ◽  
Element Method

Brake squeal phenomenon is a problem that has been long studied using multiple methods and theories. Finite Element Method (FEM) has been applied to the study of brake squeal problem. First, a disc brake model has been established. Complex mode theory has been applied to the mode analysis and unstable vibration modes can be extracted subsequently. The form of unstable vibration mode has been studied. Then, transient dynamic simulation using explicit dynamic method has been performed. Response in both time and frequency domain has been analyzed. Two methods have been compared, considering accuracy and calculation consumption. Then, the effect of different parameters such as coefficient of friction, stiffness, and brake force fluctuation frequency on squeal phenomenon has been analyzed. It can be found that coefficient of friction and the brake stiffness have a positive correlation with the extent of brake squeal phenomenon, while the frequency of brake force fluctuation should remain as low as possible. Afterwards, a ring-shaped layer of viscoelastic damping material is constrained to outer margin of the stator to restrain the unstable modal. This method can change the vibration nature and improve the brake squeal problem.

OPTIMIZATION OF INFLUENTIAL PROCESS PARAMETERS ON THE DEEP DRAWING OF ALUMINIUM 6061 SHEET USING TAGUCHI AND FINITE ELEMENT METHOD

2015 ◽  
Vol 39 (3) ◽  
pp. 605-614 ◽  
Author(s):  
Van Quang Nguyen ◽  
Balamurugan Ramamurthy ◽  
Jau-Wen Lin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Coefficient Of Friction ◽  
Process Parameters ◽  
Deep Drawing ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Edge Radius ◽  
Plastic Deformation Behavior ◽  
Element Method

The plastic deformation behavior of axis symmetric aluminium 6061 cups was determined by analyzing the four important deep drawing process parameters, namely blank temperature, die edge radius, blank holder force and friction coefficient. Taguchi techniques along with finite element method (FEM) were used to determine the importance of process parameters. The Taguchi method was used to analyze the influence of each process parameter. From the deformation result and analysis of variance (ANOVA), it was determined that the temperature of the blank has a major influence on the deformation characteristic of aluminium 6061 sheets followed by die edge radius, coefficient of friction, and blank holder force. The optimum levels of the four factors in determining the deformed cup heights are found to be blank temperature of 450°C, die edge radius of 14 mm, coefficient of friction of 0.60 and blank holder force of 9 KN.

scholarly journals Application of Numerical Simulation and Physical Modeling for Verifying a Cold Forging Process for Rotary Sleeves

2021 ◽  
Author(s):  
Tomasz Bulzak ◽  
Grzegorz Winiarski ◽  
Łukasz Wójcik ◽  
Mirosław Szala
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Tests ◽  
Simulation Software ◽  
Cold Forging ◽  
Work Piece ◽  
Geometrical Parameters ◽  
Forging Process ◽  
Forged Parts ◽  
Element Method

AbstractThis paper presents the modeling of a cold forging process for a rotary sleeve. The process of forging a EN 42CrMo4 steel part was first modeled numerically by the finite element method using simulation software DEFORM 3D ver. 11.0. After that, the developed forging process was verified by experimental tests carried out in laboratory conditions with the use of 1:2 scale tools and a material model of aluminum alloy EN AW-6060. Finite element method (FEM) results demonstrated that rotary sleeves could be formed from tubes by cold forging. Results of the experimental tests showed, however, that the material inside the hole of the work piece might not adhere to the surface of the sizing pin. Distributions of strain and stress during the forging process are determined. Geometrical parameters of forged parts obtained in experimental tests are compliant with the dimensions of forged parts simulated by FEM. In addition, experimental forces of the forging process show a high agreement with the forces obtained in FEM simulations.

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