Prediction Algorithm for WEDM Arced Path Errors Based on Spark Variable Gap and Nonuniform Spark Distribution Models

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Hamid Abyar ◽  
Amir Abdullah ◽  
Abdolhamid Akbarzadeh
Keyword(s):  
Electrical Discharge Machining ◽  
Size Variation ◽  
Discharge Frequency ◽  
Prediction Algorithm ◽  
Distribution Models ◽  
Wire Tension ◽  
Machining Errors ◽  
The Wire ◽  
Comparison Of The Results ◽  
Wire Deflection

Wire electrical discharge machining (WEDM) is a demanding high-precision process for machining of hard-to-machine materials. The main issue is manufacturing errors in shape and radius of small arcs generation. In this paper, a novel model about spark variable gap sizes and nonuniform spark distribution around the wire on arced path machining is first theoretically developed using spark angle domain and WEDM dynamic analysis. Applying spark-force distributed around the wire and resulting wire deflection are estimated by the WEDM conditions influenced by plasma channel specifications, discharge frequency, wire guide clearance, wire tension, and arc radius. Total theoretical arced machining errors including wire deflection and spark gap size variation around the wire interface are calculated based on the proposed model. In addition, machining errors of straight and small arced paths are experimentally analyzed under variation of WEDM influential parameters including discharge frequency, arced path radius (150, 300 and 450 μm), and wire tension through the statistical full factorial. Comparison of the results for different sets of variable parameters shows that the theoretical values of the arced machining errors can be consistent with the experimental one by a coefficient which depends on the machining conditions and the WED machine type. Finally, based on the theoretical and experimental results, a theoretical algorithm and an operational method with mean accuracy of 84.8% are proposed for predicting and compensating the errors of WEDM on the arced paths. Findings of this research can be used in high-accurate WEDM applications and industries.

Study on Modeling and Simulation of Wire Vibration in WEDM

2012 ◽  
Vol 472-475 ◽  
pp. 2013-2017
Author(s):  
Chao Jiang Li ◽  
Yong Feng Guo ◽  
Ji Cheng Bai ◽  
Ze Sheng Lu ◽  
Chuan Chen
Keyword(s):  
Electrical Discharge ◽  
Pulse Width ◽  
Metal Cutting ◽  
Electrical Discharge Machining ◽  
Orthogonal Design ◽  
Pulse Interval ◽  
Machining Accuracy ◽  
Wire Tension ◽  
Wire Vibration ◽  
The Wire

The wire electrical discharge machining (WEDM) has been widely used in the field of metal cutting, mold industry, aerospace and so on. However, in the discharge machining, it is very important to restrain the wire-tool vibration for the improvement of machining accuracy. In this paper, it is created a model of the wire vibration with double-ended fixed, established the differential equation of vibration, and derived its full theoretical solution to analysis the vibration factors. Simulations of the wire vibration with ANSYS Transient dynamics analysis were given. An orthogonal design of the wire vibration using L9 orthogonal table was made, and the experiment found that minimize the servo voltage, reduce the pulse width, and select the appropriate wire tension and pulse interval, which can reduce the wire vibration.

Modeling and Simulation of Wire Electrode Deflection in WEDM

2014 ◽  
Vol 541-542 ◽  
pp. 708-712
Author(s):  
Zhi Chen ◽  
He Li ◽  
Yu Huang ◽  
Zhen Zhang
Keyword(s):  
Modeling And Simulation ◽  
Electrical Discharge Machining ◽  
Negative Impact ◽  
Electrostatic Force ◽  
Simulation Method ◽  
Impact Factors ◽  
Machining Accuracy ◽  
Wire Electrode ◽  
The Wire ◽  
Wire Deflection

In the process of wire electrical discharge machining, the wire electrode inevitably suffers bending deformation due to wire tension, electrostatic force, electrodynamics force, etc., and the deflection would make an clearly negative impact upon the machining accuracy, productivity and stability. In this paper, first of all, a novel modeling and simulation method is proposed for quantitatively calculating the wire deflection. Secondly, the mainly impact factors and trend of wire deflection have been concluded. Moreover, the feasibility of the model is proved by comparing with other researchers models. Eventually, the practical approaches of reducing wire deflection and improving the machining accuracy have been proposed.

scholarly journals Influence of Energy Parameters of Micro WEDM on Kerf

2012 ◽  
Vol 576 ◽  
pp. 527-530
Author(s):  
Mohammad Yeakub Ali ◽  
W.Y.H. Liew ◽  
S.A. Gure ◽  
B. Asfana
Keyword(s):  
Experimental Data ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Kerf Width ◽  
Wire Electrical Discharge Machining ◽  
Machining Parameters ◽  
Wire Electrode ◽  
Wire Vibration ◽  
The Wire ◽  
Micro Wedm

This paper presents the estimation of kerf width in micro wire electrical discharge machining (micro WEDM) in terms of machining parameters of capacitance and gap voltage. An empirical model is developed by the analysis of variance (ANOVA) of experimental data. Using a wire electrode of 70 µm diameter, a minimum kerf width is found to be 92 µm for the micro WEDM parameters of 0.01 µF capacitance and 90.25 V gap voltage. Around 30% increament of the kerf is found to be high. The analysis also revealed that the capacitance is more influential parameter than gap voltage on kerf width produced by micro WEDM. As the gap voltage determines the breakdown distance and affects the wire vibration, the wire vibration factor is to be considered in the analysis and in formulation of model in future study.

scholarly journals EVALUATION AND SELECTION OF THE METHOD FOR CONTROL SYSTEM THE WIRE TENSION IN CUT-OUT ELECTRIC EROSION MACHINES

2021 ◽  
pp. 47-50
Author(s):  
M. N. Buza ◽  
N. O. Butusov ◽  
A. S. Voronin ◽  
A. G. Alekhin
Keyword(s):  
Control System ◽  
Wire Tension ◽  
Electric Erosion ◽  
The Wire ◽  
Selection Of

Variants of the electrode tension mechanism in an electric erosion machine are considered in order to ensure a quick change of the electrode thread and the required degree of tension.

scholarly journals Improving Electrical Discharge Machining Process for Bodies of Rotation

2020 ◽  
pp. 313-324
Author(s):  
Victor Bokov ◽  
◽  
Oleh Sisa ◽  
Vasyl Yuryev ◽  
◽  
...  
Keyword(s):  
Working Conditions ◽  
Sliding Friction ◽  
Electrical Discharge Machining ◽  
Electric Arc ◽  
Working Fluid ◽  
Wire Electrode ◽  
Electrode Tool ◽  
Electrode Holder ◽  
The Wire ◽  
Machining Productivity

In modern mechanical engineering, electrical discharge machining (EDM) methods are widely used for machining bodies of rotation from difficult-to-machine materials. Those methods ensure sparing cutting and make it possible to machine any electrically conductive material irrespective of its physical and chemical properties, in particular hardness. There is a known method for dimensional machining of bodies of rotation with electric arc using a wire electrode tool that is pulled along in the machining area thus "compensating" for that tool's EDM wear and tear. The machining accuracy is therefore significantly heightened. However, when implementing this method, an effect of splashing the working fluid outside the working area of the machine and a pronounced luminous effect from the burning of the electric arc in the machining area are observed. That worsens the working conditions. In addition, when pulling the wire electrode tool along the convex surface of the electrode holder, the sliding friction arises, which eventually leads to mechanical destruction of the contact point. As a result, a deep kerf is formed on the electrode holder. When the depth of the kerf reaches the diameter of the wire electrode tool, the destruction of the electrode holder by the electric arc begins. Consequently, the durability of the electrode holder in the known method is unsatisfactory. A method of dimensional machining of bodies of rotation with electric arc using a wire electrode tool with the immersion of the machining area in the working fluid has been proposed, which makes it possible to improve the working conditions of the operator by eliminating the effect of fluid splashing and removing the luminous effect of arc burning in the machining area. In addition, it has been proposed to make the electrode holder in the form of a roller that rotates with a guide groove for the wire electrode tool, while the nozzle for creating the transverse hydrodynamic fluid flow has been proposed to be mounted in a separate fixed housing that is adjacent to the electrode holder. This technical solution replaces the sliding friction with the rolling one thus enhancing the durability of the electrode holder. Mathematical models of the process characteristics of the DMA-process (dimensional machining with electric arc) for bodies of rotation using a wire electrode tool with the immersion of the machining area in the working fluid have been obtained that make it possible to control the machining productivity, the specific machining productivity, the specific electric power consumption, and the roughness of the surface machined.

Interaction Between Wire and Ingot in Wiresaw Slicing

1999 ◽  
Author(s):  
Fuqian Yang ◽  
J. C. M. Li ◽  
Imin Kao
Keyword(s):  
Finite Element ◽  
Contact Zone ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Bending Stiffness ◽  
Mechanical Interaction ◽  
Wire Tension ◽  
Cutting Zone ◽  
The Wire

Abstract The deformation of the wire in the wiresaw slicing process was studied by considering directly the mechanical interaction between the wire and the ingot. The wire tension on the upstream is larger than on the downstream due to the friction force between the wire and the ingot. The tension difference across the cutting zone increases with friction and the span of the contact zone. The pressure in the contact zone increases from the entrance to the exit if the wire bending stiffness is ignored. The finite element results show that the wire bending stiffness plays an important role in the wire deformation. Higher wire bending stiffness (larger wire size) generates higher force acting onto the ingot for the same amount of wire deformation, which will leads to higher material removal rate and kerf loss. While larger wire span will reduce the force acting onto the ingot for a given ingot displacement in the direction perpendicular to the wire.

scholarly journals Wire Electrical Discharge Machining—A Review

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 69
Author(s):  
Laurenţiu Slătineanu ◽  
Oana Dodun ◽  
Margareta Coteaţă ◽  
Gheorghe Nagîţ ◽  
Irina Beşliu Băncescu ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Wire Electrical Discharge Machining ◽  
Wire Electrode ◽  
Machining Processes ◽  
Scientific Papers ◽  
The Wire ◽  
Machining Productivity ◽  
Machined Surfaces

Wire electrical discharge machining has appeared mainly in response to the need for detachment with sufficiently high accuracy of parts of plate-type workpieces. The improvements introduced later allowed the extension of this machining technology to obtain more complex ruled surfaces with increasingly high requirements regarding the quality of the machined surfaces and the productivity of the wire electrical discharge machining process. Therefore, it was normal for researchers to be interested in developing more and more in-depth investigations into the various aspects of wire electrical discharge machining. These studies focused first on improving the machining equipment, wire electrodes, and the devices used to position the clamping of a wire electrode and workpiece. A second objective pursued was determining the most suitable conditions for developing the machining process for certain proper situations. As output parameters, the machining productivity, the accuracy, and roughness of the machined surfaces, the wear of the wire electrode, and the changes generated in the surface layer obtained by machining were taken into account. There is a large number of scientific papers that have addressed issues related to wire electrical discharge machining. The authors aimed to reveal the aspects that characterize the process, phenomena, performances, and evolution trends specific to the wire electrical discharge machining processes, as they result from scientific works published mainly in the last two decades.

scholarly journals Design and Analysis of a Wire-Driven Parallel Mechanism for Low-Gravity Environment Simulation

2014 ◽  
Vol 6 ◽  
pp. 810606 ◽  
Author(s):  
Weifang Wang ◽  
Xiaoqiang Tang ◽  
Zhufeng Shao ◽  
Jiping Yang ◽  
Wangmin Yi
Keyword(s):  
Parallel Mechanism ◽  
Quality Index ◽  
Parallel Manipulator ◽  
Force Distribution ◽  
The Moon ◽  
Low Gravity ◽  
Wire Tension ◽  
Environment Simulation ◽  
The Wire ◽  
And Control

Traditional simulation mechanisms are unable to meet the simulation requirements of spacecraft launcher in low-gravity environment, like in the Moon. Based on the advantages of wire-driven parallel mechanism, a 6-DOF low-gravity environment simulation device with eight wires is designed in this paper. Firstly, the configuration and dimensional design of this wire-driven parallel mechanism are carried out. To operate and control the wire-driven parallel mechanism, a force distribution algorithm is introduced and the workspace is analyzed. Then, an evaluation index named quality index is established in order to study the performance of the wire-driven parallel manipulator in its workspace and reasonable tension is obtained after analyzing the influence on quality index caused by different wire tension.

The effect of clamping a tensioned wire: Implications for the Ilizarov external fixation system

2003 ◽  
Vol 217 (2) ◽  
pp. 91-98 ◽  
Author(s):  
M A Watson ◽  
K J Mathias ◽  
N Maffulli ◽  
D W L Hukins
Keyword(s):  
Finite Element ◽  
Standard Deviation ◽  
External Fixator ◽  
Clinical Situation ◽  
Engineering Problem ◽  
Fe Model ◽  
Ilizarov External Fixator ◽  
Wire Tension ◽  
The Wire ◽  
Fixation System

This study demonstrates that clamping a tensioned wire can cause a reduction in wire tension. Tension (about 1275 N) was applied to a wire that was subsequently clamped, using cannulated bolts, to the steel half-ring of an Ilizarov external fixator. The tension in the wire was monitored before, during and after clamping. The apparatus was disassembled and the deformations in the wire caused by the clamps were measured. This experiment was repeated 15 times. When the wire was clamped to the frame, the wire tension was reduced by 22 ± 7 per cent (mean ± standard deviation, SD). The drop in wire tension was linearly correlated ( r = 0.96; p < 0.001) with the deformation caused by the bolts. A finite element (FE) model of the wire was also constructed. The model was pre-stressed (tensioned), and the clamping effect replicated. This analysis showed that clamping the wire could be considered to squeeze the wire outwards (like toothpaste from a tube) and so reduce its tension during fixator assembly. To assess the magnitude of this effect in the clinical situation, the FE model analysis was repeated to replicate clamping a 1.8-mm-diameter wire to a 180-mm-diameter steel Ilizarov ring component. The analysis showed that for these conditions the tension reduced by 8–29 per cent. The results of this study highlight a general engineering problem: how can a tensioned wire be secured to a structure without an appreciable loss of tension? If the performance of the structure depends on the wire tension, this performance will change when the wire is secured.

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