Papers by Keyword: Wire Tension

Abstract: Wire tension as well as wire feed should be controlled tightly for the geometry and corner accuracy of wire-EDM. A closed-loop wire tension control system for Micro-Wire-EDM is presented to guarantee a smooth wire transport and a constant tension value. To keep smooth wire transportation and avoid wire breakage during wire feeding, the reel roller is modified and the clip reel is removed from the wire transport mechanism. A genetic algorithm-based fuzzy logic controller (FLC) is proposed to investigate the dynamic performance of the closed-loop wire tension control system. Theoretical analysis and experimental research demonstrate that the developed wire transport system can result in satisfactory transient response, steady-state response and robustness. The proposed FLC can obtain faster transient response and smaller steady-state error than PI controller.

Abstract: For the multiple solutions of wire tensions to wire-driven parallel manipulator, the paper presents a wire tension optimization program based on the penalty function. After building a nonlinear programming model and simulating in MATLAB, the optimal solution of wire tensions under the minimal preload is calculated. Compared with the simulation results and experimental results, it shows that the wire tensions in experiment are relatively stable and the trends are overall consistent with the simulation results. The study lays a foundation for selecting the suitable preload for the wire-driven parallel manipulator.

Abstract: Titanium is present in the earth’s crust at a level about 0.6% and is therefore the fourth most abundant structural metal after aluminum, iron, and magnesium. High strength, low density, and excellent corrosion resistance are the main properties that make titanium attractive for a variety of applications. The major application of the material is in the aerospace industry, both in airframes,engine components,steam turbine blades, superconductors, missiles etc. or corrosion resistance, for example marine services, chemical, petrochemical, electronics industry, biomedical instruments etc.In this study, wire electrical discharge machining (WEDM) is adopted in machining of commercially pure titanium (Grade-2). During experiments, parameters such as Pulse on time, Pulse off time, Peak current, Spark Gap set Voltage, Wire Feed and Wire Tension were changed to explore their effect on the cutting rate, gap current and surface roughness of the machined specimens. The ranges of process parameters for the experiments were decided on the basis of literature survey and the pilot experiments conducted using one factor at a time approach(OFTA). It is found that the intensity of the process energy does affect the cutting rate, gap current and surface roughness as well as, the wire speed, wire tension and dielectric fluid pressure not seeming to have much of an influence.