Influence of Tool - Semi-Product Friction on the Force Evolution at the Simulation of the Deformation Process with Flat Wedge Tools

2013 ◽  
Vol 837 ◽  
pp. 93-98
Author(s):  
Doina Iacomi ◽  
Monica Iordache ◽  
Eduard Niţu ◽  
Stefan Tabacu
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Friction Coefficient ◽  
Deformation Process ◽  
Design Stage ◽  
Cold Plastic Deformation ◽  
High Productivity ◽  
Hardening Law ◽  
Deformation Force ◽  
As Stress

Processing through volumetric cold plastic deformation (cold rolling) with flat wedge tools is a procedure used in mass production to process profiles (circular, threads, grooves, teeth) on revolution pieces. Complex profiles obtained by cold plastic deformation with flat wedge tools have important advantages: material economy, high productivity, continuous fibre, superior mechanic properties, low values of the roughness parameters, low costs. In recent years, the simulation of processes of volumetric plastic deformation by the finite element method is used to obtain the optimization of the deformation process and the improvement of the product quality even from the design stage. By numerical simulation there is observed the evolution during the process of different parameters such as: stress and deformations in the deformed body, mode of material flow, final shape and sizes of the product etc. Therefore, it becomes possible to analyse the process even from the design stage by identifying the problems which can appear and their influence on some characteristics of the product obtained: geometry, state of deformations and stress.This paper presents the experimental determination of the deformation force at the processing of complex profiles with flat wedge tools and the influence of the friction coefficient between tool and semi-product on its value; influence established by simulating the deformation process. The process also has been simulated by means of finite element calculations using the Abaqus/Explicit code. The material behaviour is described by using a 5-parameter strain-hardening law and by accounting for thermal effects at high strain-rates. The comparison between the values and the variation of the deformation force recorded experimentally and at simulation allows establishing the optimal value of the friction coefficient and validating the numerical model developed.

Plastic Crushing Behavior of Thin-Walled Spheres

2008 ◽  
Vol 33-37 ◽  
pp. 719-724
Author(s):  
P. Xue ◽  
J.P. He ◽  
Yu Long Li
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Deformation Process ◽  
Experimental Result ◽  
Plastic Deformation Process ◽  
Post Buckling ◽  
Thin Walled ◽  
Crushing Behavior

Plastic crushing behavior of thin-walled spheres under various loading cases is studied using Finite Element Method. The entire plastic deformation process is tracked during the post-buckling process. The results are compared with the experimental results reported in literature [13], and very good agreements between the numerical simulation and the experimental result are achieved.

A Finite Element Model for Spherical Debris Denting in Heavily Loaded Contacts

2004 ◽  
Vol 126 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Young Sup Kang ◽  
Farshid Sadeghi ◽  
Mike R. Hoeprich
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Friction Coefficient ◽  
Aspect Ratio ◽  
Finite Element Model ◽  
Contact Force ◽  
Material Properties ◽  
Element Model ◽  
Friction Coefficients ◽  
Elastic Plastic

The objective of this study is to develop models to investigate the effects of contaminants (debris denting process) in heavily loaded rolling and sliding contacts. A dynamic time dependent finite element model (FEM) was developed to determine the elastic-plastic deformation and contact force generated between the mating surfaces and a spherical debris as debris passes through the contact region. The FEA model was used to obtain the effects of various parameters such as debris sizes, material properties, friction coefficients, applied loads, and surface speeds on the elastic-plastic deformation and contact force of the system. The FEM was used to predict debris and mating surfaces deformations as a function of debris size, material properties, friction coefficient, applied load, and surface speed. Using the FEM, a parametric study demonstrated that material properties (i.e., modulus of elasticity, yield strength, ultimate strength and Poisson’s ratio) and friction coefficients play significant roles on the height and width of dents on the mating surfaces. For lower friction coefficients μd<0.3 the debris and mating surfaces slip more easily relative to one another and therefore the debris has lower aspect ratio. As friction coefficient is increased the debris and mating surfaces stick to one another and therefore the debris deforms less and has higher aspect ratio. The results indicate that the pressure generated between the debris and mating surfaces is high enough to plastically deform the debris and mating surfaces and cause a permanent dent on the surfaces and cause residual stresses around the dent. Based on the FEM results, a dry contact model (DCM) was developed to allow similar analyses as the FEM, however, in significantly shorter computational time.

Finite Element Method in the Research on the Application of Contact Deformation

2012 ◽  
Vol 182-183 ◽  
pp. 1585-1589 ◽  
Author(s):  
Jia Jia Su ◽  
Jing Hu Chen
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Stress State ◽  
Friction Coefficient ◽  
Contact Deformation ◽  
Matrix Surface ◽  
The Matrix ◽  
State Changes ◽  
Element Method

Wear is the matrix surface and plastic deformation as the basic factors of the phenomenon, this paper analyzed with abaqus finite element method friction deformation which stress. The results show that the stress state changes drastically with different friction coefficient and the distribution of plastic deformation regions also changes. The regions seriously damaged by friction lead to fatigue via plastic deformation, which is the main reason for material friction and then dislocation friction occurs.

scholarly journals Effects of varying friction coefficient on rolling pressure distribution

2019 ◽  
Vol 37 (2) ◽  
pp. 11-25
Author(s):  
F. Davis ◽  
A. Andrews ◽  
M. N. Sackey ◽  
S. P. Owusu-Ofori
Keyword(s):  
Plastic Deformation ◽  
Friction Coefficient ◽  
Pressure Distribution ◽  
Deformation Process ◽  
Contact Region ◽  
Quantitative Relationship ◽  
Current Approach ◽  
Roll Pressure ◽  
Constant Friction ◽  
Variable Friction

Accurate characteristics of roll pressure distribution is essential in the estimation of the energy and power requirements for parts undergoing plastic deformation. The nature of the pressure distribution is very sensitive to the friction coefficient between the roller and the deformed part. The physics of the deformation process points to a variable friction coefficient, however, current research and practices result in the use of a constant friction coefficient. This work explored the development of a technique to determine a quantitative relationship between the variable friction coefficient and the process parameters. The pressure distribution was then developed within the contact region using the variable friction coefficient model. Results show that current approach used by industry (‘the rule of thumb’) overestimates the pressure distribution, compared to the current research, thus wasting power needed for the rolling operation by about 18%. Keywords: Rolling; varying friction coefficient; pressure distribution; power 

Finite Element Analysis on Plastic Deformation Behaviors of Ti-3Al-2.5V Tubes under Axial Compression

2015 ◽  
Vol 639 ◽  
pp. 551-558 ◽  
Author(s):  
Tao Huang ◽  
Mei Zhan ◽  
Jin Qiang Tan ◽  
Jing Guo ◽  
He Yang
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Flow Stress ◽  
Friction Coefficient ◽  
Axial Compression ◽  
High Performance ◽  
Fe Model ◽  
Deformation Degree ◽  
Element Analysis ◽  
Deformation Behaviors

With the requirement of aviation and aerospace fields for high-strength Ti-3Al-2.5V titanium alloy bent tubes with high-performance, it is great significance to research the plastic deformation of Ti-3Al-2.5V tubes under compression to obtain desired flow stress curves. A finite element (FE) model of axial compression of Ti-3Al-2.5V tubes was established in this study. Using this model, deformation behaviors of Φ12 mm × t0.9 mm Ti-3Al-2.5V tubes with different ratios of thickness to height (t/h) compressed under different frictions were analyzed. It is shown that the non-uniform deformation degree of the tubes increases with the decrease of t/h and the increase of friction coefficient. This means that a large t/h value and small friction can help to attain a uniaxial compression condition to obtain desired flow stress curves. Such compression conditions for the Φ12 mm × t0.9 mm Ti-3Al-2.5V tube is that, t/h is not less than 0.6 and the friction coefficient is not greater than 0.05

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