This work aims to show that the Boundary Element Method (BEM) is ideally suited for two-dimensionaL prediction of workpiece shapes for given tooling, and evaluation of tool profiles for known workpiece forms in Electrochemical Machining (ECM). A critical review of existing techniques for modelling ECM is presented which is followed by a resume of BEM. A few 'static' potential problems are analysed using BEM programs with constant, linear and quadratic elements before concentrating upon the two. ECM shape probLems. A number of complex-shaped tool profiles are used for simuLated ECM ceLLs. The effects of boundary mesh and time step size, eLement type and method of moving the work boundary upon accuracy of the resulting work profile are examined. The capabilities of the BEM based model to cater for over-potential and variable eLectrolyte conductivity conditions are also considered. Computed work shapes are shown to correlate well with exact and experimental solutions obtained from various sources. In some cases, BEM is shown to be superior to other established numerical techniques. Evaluation of tool profiles in this work is limited to fully conducting profiles only. It is iterative in nature and uses the approximate cos θ method to initiate the. procedure. Subsequent iterations employ formulations developed herein to correct tool profile to satisfy work boundary conditions. Effects of element type and merits of specifying different boundary conditions on the work surface are assessed. Computed tool profiles, when used in the machining model, are shown to yield desired workpiece shapes. Finally, general conclusions and a few suggestions for 'future research complete the thesis.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:488032 |
| Date | January 1985 |
| Creators | Narayanan, O. H. |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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