FEM Analysis of Helical Rolling of Steel Balls

2013 ◽  
Vol 572 ◽  
pp. 525-528 ◽  
Author(s):  
Zbigniew Pater
Keyword(s):  
Process Parameters ◽  
Effective Strain ◽  
Fem Analysis ◽  
Helical Rolling ◽  
Damage Criterion ◽  
Advantages And Disadvantages ◽  
Roll Wear ◽  
Software Program ◽  
Steel Balls

In this paper, two helical rolling processes for producing balls with a diameter of 40 mm are compared – the traditionalrolling and wedge rolls rolling. The process analyses were performed using Simufact.Forming, a FEM-based software program, and the same process parameters were applied in the analyses. Based on the calculations results (the distributions of effective strain, damage criterion, roll wear as well as the variations of forces and rolling moments during the processes), advantages and disadvantages of the considered rolling methods could be presented.

scholarly journals Effect of the Forming Zone Length on Helical Rolling Processes for Manufacturing Steel Balls

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2917 ◽  
Author(s):  
Andrzej Gontarz ◽  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Effective Strain ◽  
Cost Effective ◽  
The Finite Element Method ◽  
Helical Rolling ◽  
Zone Length ◽  
Tool Service Life ◽  
Tool Service ◽  
Steel Balls

This paper begins with a brief overview of the methods for producing balls. It then discusses the rolling processes for producing balls in helical passes. Next, a method for designing tools for helical rolling (HR) is described. Six different cases of rolling using tools with helical passes of different lengths are modeled by the finite element method (FEM). The simulations are performed with the use of Simufact Forming version 13.3. Based on the 3D simulations, the distributions of effective strain, damage criterion, and temperature, as well as the variations in loads and torques, are determined. This study also predicts the rate and manner of wear of the helical tools, depending on the tool design. As a result, it has been found that an increased length of the helical forming passes is advantageous in terms of tool service life. It has also been found that excessive elongation of the forming zone is not cost-effective.

scholarly journals Experimental and Numerical Study of Cold Helical Rolling of Small-Diameter Steel Balls

2021 ◽  
Author(s):  
Shengqiang Liu ◽  
Jinping Liu ◽  
Hao Xu ◽  
Zhipeng Wang ◽  
Jinxia Shen ◽  
...  
Keyword(s):  
Work Hardening ◽  
Fe Simulation ◽  
Numerical Study ◽  
Rolling Force ◽  
Effective Strain ◽  
Small Diameter ◽  
Helical Rolling ◽  
Forming Process ◽  
Cold Forming ◽  
Steel Balls

Abstract Cold helical rolling (CHR) is one of the most effective ways to produce small-diameter steel balls. In this study, one kind of work hardening model was established and implemented into Simufact 15.0 to investigate the work hardening phenomenon in the cold forming process. Firstly, based on the helical rolling theory, a set of finite element (FE) simulations was developed. The influence of CHR parameters, including the starting height of convex rib, forming area length, and rolling inclination angle, on the forming process was studied via simulation. Furtherly, the CHR process experiments and FE simulation were carried out , the results showed that the FE simulation was in good agreement with the experimental results, and consistent with the predicted value of the theoretical calculation. Finally, the evolution of effective strain, effective stress, rolling force, work hardening and microstructure during the cold helical rolling of Φ 5.12 mm steel balls was investigated via FE. As result, the evolution trend of hardness was consistent with that of dislocation density, indicating that the model is credible. Besides, the microstructure of the steel ball at different positions further verified this.

BLOOD FLOW SIMULATION USING SPH METHOD IN LS-DYNA, ANALYSIS OF ADVANTAGES AND DISADVANTAGES

2021 ◽  
Author(s):  
Marko Topalovic ◽  
◽  
Aleksandar Nikolic ◽  
Miroslav Zivkovic
Keyword(s):  
Blood Flow ◽  
Flow Simulation ◽  
Fem Analysis ◽  
Sph Method ◽  
Shell Elements ◽  
Advantages And Disadvantages ◽  
Fluid Analysis ◽  
Eulerian Formulation ◽  
Mesh Free ◽  
Modelling Methodology

The purpose of this research was to investigate the possibility of blood flow modelling in LS-DYNA using its SPH solver and SPH-FEM coupling. SPH and FEM methods are both based on the continuum mechanics, and SPH uses Lagrangian material framework, while FEM can use both Lagrangian for solid, and Eulerian formulation for fluid analysis. SPH implementation is mesh-free giving it the capability to model very large deformations without mesh distortions. However, this comes at a high computational price, so the number of SPH particles needs to be significantly lower in comparison to the number of FEM elements in the Eulerian analysis of the same fluid domain. In the case of combined SPH-FEM analysis, the blood vessel wall is modelled with FEM shell elements, while the blood inside is modelled with SPH particles. The contact between the two is done using nodes to surface algorithm, while if we use the SPH only, there is no need for the specific contact definition. The Lagrangian framework of the SPH method means that we need to generate particles at one end, and to destroy them on the other, in order to generate a continuous fluid flow. To do this we used activation and deactivation planes, which is a solution implemented in the commercial LS-Dyna SPH solver. In the results section of the paper, the velocity field of blood obtained by implementation of described modelling methodology is shown. SPH-FEM coupling offers greater possibilities to study the effects of wall deformations, tracking of movement of solid particle inclusion, or mixing two different fluids, but it requires elaborate contact definition, and prolonged analysis time in comparison to the FEM CFD analysis.

scholarly journals Physical Modelling of the Ball-Rolling Processes

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 35 ◽  
Author(s):  
Zbigniew Pater ◽  
Janusz Tomczak ◽  
Łukasz Wójcik ◽  
Tomasz Bulzak
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Physical Modelling ◽  
Model Material ◽  
Helical Rolling ◽  
Rolling Mills ◽  
Cross Rolling ◽  
Plastic Forming ◽  
3D Printed ◽  
Manufacturing Accuracy ◽  
Steel Balls

The objective of the article was to present the state of the problem of physical modelling of the hot-working processes with plasticine as the model material. It was stated that the aforementioned method can prove helpful in analyzing complex plastic forming processes such as cross rolling and helical rolling of balls. In order to confirm this hypothesis, an attempt at forming steel balls with diameters of 40 mm (cross rolling) and 57 mm (helical rolling) under laboratory conditions was made. Further on, these processes were conducted in model form using special model rolling mills and 3D printed acrylonitrile butadiene styrene (ABS) tools. The comparison of the test results regarding shape and manufacturing accuracy, as well as force parameters, confirmed the validity of using physical modelling in the investigation of the process of cross rolling and helical rolling of balls.

scholarly journals Reconfigurable Multipoint Forming Using Waffle-Type Elastic Cushion and Variable Loading Profile

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4506
Author(s):  
Mohammed Moheen ◽  
Adel Abdel-Wahab ◽  
Hany Hassanin ◽  
Khamis Essa
Keyword(s):  
Process Parameters ◽  
Fem Analysis ◽  
Thickness Variation ◽  
Variable Loading ◽  
Shape Deviation ◽  
Multipoint Forming ◽  
Base Radius ◽  
Manufacturing Techniques ◽  
Elastic Cushion ◽  
Reconfigurable Die

There is an increasing demand for flexible, relatively inexpensive manufacturing techniques that can accommodate frequent changes to part design and production technologies, especially when limited batch sizes are required. Reconfigurable multi-point forming (MPF) is an advanced manufacturing technique which uses a reconfigurable die consisting of a set of moveable pins to shape sheet metal parts easily. This study investigates the use of a novel variable thickness waffle-type elastic cushion and a variable punch-loading profile to either eliminate or minimise defects associated with MPF, namely wrinkling, thickness variation, shape deviation, and dimpling. Finite element modelling (FEM), analysis of variance (ANOVA), and the response surface methodology (RSM) were used to investigate the effect of process parameters pertaining to the cushion dimensions and type of loading profile on the aforementioned defects. The results of this study indicate that the most significant process parameters were maximum cushion thickness, cushion cut-out base radius, and cushion cut-out profile radius. The type of loading profile was found to be insignificant in all responses, but further investigation is required as the rate, and the thermal effects were not considered in the material modelling. Optimal process parameters were found to be a maximum cushion thickness of 3.01 mm, cushion cut-out base radius of 2.37 mm, cushion cut-out profile radius of 10 mm, and a “linear” loading profile. This yielded 0.50 mm, 0.00515 mm, 0.425 mm for peak shape deviation, thickness variation, and wrinkling, respectively.

scholarly journals Experimental and FEM Analysis of Void Closure in the Hot Cogging Process of Tool Steel

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 538 ◽  
Author(s):  
Marcin Kukuryk
Keyword(s):  
Hydrostatic Stress ◽  
Effective Strain ◽  
Three Dimensional ◽  
Stress Triaxiality ◽  
Fem Analysis ◽  
Experimental Tests ◽  
Reduction Ratio ◽  
Compression Process ◽  
Void Closure ◽  
Axial Defects

In the present study, a new complex methodology for the analysis the closure of voids and a new forging system were developed and tested. The efficiency of the forging parameters and the effective geometric shapes of anvils to improve void closure were determined. A new cogging process provided a complete closure of an ingot’s axial defects, as confirmed by experimental tests. The evolution behavior of these defects with different sizes was investigated during the hot cogging process by means of the professional plastic forming software Deform-3D. A comprehensive procedure was developed using the finite-element method (FEM) for the three-dimensional cogging process and laboratory experimentation to predict the degree of void closure. The hot multi-pass cogging process was used to eliminate void defects in the forgings so as to obtain sound products. In the compression process, the effects of the reduction ratio and forging ratio, the void size, and the types of anvil were discussed to obtain the effective elimination of a void. For the purpose of the assessment of the effectiveness of the void closure process, the following indices were introduced: the relative void volume evolution ratio, the relative void diameter ratio, and the internal void closure evaluation index. Moreover, the void closure process was assessed on the basis of stress triaxiality, hydrostatic stress, forging ratio, value of local effective strain around the void, and critical reduction ratio. The results of this research were complemented by experiments predicting the formation of fractures in the regions near the void and in the volume of the forging in the course of the cogging process. The comparison between the predicted and the experimental results showed a good agreement.

A Study on Development of Forming Roller for Miniature Metal Balls Manufacturing Process

2007 ◽  
Vol 539-543 ◽  
pp. 2518-2523
Author(s):  
H.S. Joe ◽  
J.S. Park ◽  
Y.H. Kim
Keyword(s):  
Process Parameters ◽  
Manufacturing Process ◽  
Manufacturing System ◽  
Fem Simulation ◽  
Basic Design ◽  
Knife Edge ◽  
Processing Parameter ◽  
Processing Property ◽  
Rigid Plastic ◽  
Steel Balls

According as the demand of miniature metal balls of various diameter increases, processing property and a variety of coverage are important. In this study, especially an optimal groove design of cutting roller was investigated for determining size and shape of metal ball in the manufacturing system. The effects of radius of the groove and radius of the knife-edge of cutting roller and the speed of roller as process parameters were calculated and analyzed. We applied data of rigid-plastic FEM Simulation with DEFORM3D and ANSYS in basic design of equipment to solve these issues, and checked processing parameter about metal balls manufacturing process that use cutting process of metal wire stock in this research. This paper deals with the new improved process of producing miniature STS316L steel balls continuously. Our first goal is to develop a much more efficient equipment and a much more economical production process

Analysis on Void Closure Behavior during Hot Open Die Forging

2007 ◽  
Vol 26-28 ◽  
pp. 69-72 ◽  
Author(s):  
Young Seon Lee ◽  
Y.C. Kwon ◽  
Yong Nam Kwon ◽  
Jung Hwan Lee ◽  
S.W. Lee ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Effective Strain ◽  
Fem Analysis ◽  
Void Closure ◽  
X Ray ◽  
Die Forging ◽  
Before And After ◽  
Measured Flow ◽  
Flow Stress Data ◽  
Open Die Forging

Internal voids have to be eliminated for defect-free in some open die forging. The FEM analysis is performed to investigate the overlap defect of cast ingots during cogging stage. The measured flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the numerical analysis of void closure is performed by using the DEFORMTM-3D. The calculated results of void closure behavior are compared with the measured results before and after upsetting, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the void closure were estimated into effective strain of 0.6 by the comparison of practical experiment and numerical analysis.

Behavior evaluation and effects of different lubricants in ECAP process

2017 ◽  
Vol 69 (5) ◽  
pp. 701-707
Author(s):  
Seyed Husein Hasani Najafabadi ◽  
Ali Akbar Lotfi Neyestanak ◽  
Saeed Daneshmand
Keyword(s):  
Friction Coefficient ◽  
Process Parameters ◽  
Effective Strain ◽  
Mesh Size ◽  
Industrial Applications ◽  
Zinc Stearate ◽  
Content Type ◽  
Practical Applications ◽  
Angular Pressing ◽  
Ecap Process

Purpose The purpose of equal channel angular pressing (ECAP) is producing ultra-fine grain materials. In practical applications, it is important to understand and predict effect of different process parameters on deformed parts. One of the most important process parameters is friction coefficient. Behavior evaluation of different lubricants in the ECAP process is the aim of this research. Design/methodology/approach The present study concerns the experimental measurements of the effective strain by means of gridded parts for three different lubricants, graphite, molybdenum disulfide and zinc stearate, to evaluate friction coefficient in ECAP process. Mesh size was 2 × 2 mm2 and embedded in parts made of AL2024; process was done in ambient temperature, and parts were in annealed situation. After the process, strain measured by optical and analytical methods for evaluation of lubricants’ behavior with different friction coefficients. Findings This study shows that zinc stearate has better effects rather than other lubricants in ECAP process and ECAPed parts. Originality/value The fatal challenge for researchers and industrial applications of ECAP process is lubrication. This research is a guide for scientists and engineers (in the future applications) to reduce and control bad frictional effects, produce better parts (more strain homogenous parts), prevent die failures and decrease press tonnage in ECAP process.

Study on the method for groove design in the helical rolling of steel balls

1995 ◽  
Vol 55 (3-4) ◽  
pp. 340-344 ◽  
Author(s):  
Wang Quanxian ◽  
Wang Qiping ◽  
Xiao Jianming
Keyword(s):  
Helical Rolling ◽  
Groove Design ◽  
Steel Balls
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