Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 13, 2008) Vita. Includes bibliographical references.

Thesis (Ph.D.(Mechanical Engineering))--University of Pretoria, 2001. Includes bibliographical references. / Summaries in Afrikaans and English.

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2007. / Dr. Liang, Steven Y., Committee Chair ; Dr. Melkote, Shreyes N., Committee Member ; Dr. Vengazhiyil, Roshan Joseph, Committee Member ; Dr. Zhou, Chen, Committee Member ; Dr. Zhou, Min, Committee Member.

M.Ing. / A large number of machine tools in use today are worn and can not produce the correct tolerances as a result of the inaccuracy of the structure. A device was developed to assist in the solution to the problem. The study of the development of this device includes several different fields. An entire prototype scale model of a grinding device is developed, with components including a control system and a developed sensor. The control system consists of circuitry and programming. The programming has been done in Visual Basic. The circuitry includes driver circuits for DC motors as well as pulse width modulation circuits and filters, amplifiers and comparators for the newly developed sensors. The sensor developed is an optical device, which can sense the deviation of a cable for reference for the movement of the device. A combination of the above components into a unit and the provision for factors, such as grinding forces and vibrations, which influence the operation of the device, are presented. Furthermore, an analytical model is suggested for the prediction of the system's behavior.

Electrical Discharge Machining (EDM) is a non-contact manufacturing process in which material is removed from a metal workpiece by high frequency electrical pulses produced between an electrode and the workpiece. EDM machines are usually stand-alone devices, and are quite expensive. The objective of this research was to integrate an EDM machine and an existing reconfigurable CNC machine tool, using a modular approach, to enable conventional milling and EDM to be conducted in a co-ordinated fashion on the same machine tool.

No description available.

Advanced manufacturing machinery is a corner stone of essential industries of technologicallydeveloped societies. Their accuracy permits the production of complexproducts according to tight geometric dimensions and tolerances for high efficiency,interchangeability and sustainability. The accuracy of advanced manufacturingmachinery can be quantified by the performance measure of positioning accuracy.Positioning accuracy measures the closeness between a commanded and an attainedposition on a machine tool or industrial manipulator, and it is ruled by lawsof physics in classical mechanics and thermodynamics. These laws can be applied tomodel how much the machinery deflects due to gravity, expands due to a change intemperature and how much and how long it vibrates due to process forces; hence,one can quantify how much the accuracy decreases. Thus, to produce machinerywith ever higher accuracy and precision one can design machines which deflect,expand and vibrate less or one can understand and model the actual behaviour ofthe machinery to compensate for it.This licentiate thesis uses physics-based modelling to quantify the positioningaccuracy of machine tools and industrial robots. The work investigates the potentialincrease in positioning accuracy because of the simultaneous modelling of the kinematics,static deflections, vibrations and thermo-elasticity as a lumped-parametermodel of the machinery. Consequently the models can be used to quantify thechange of the accuracy throughout the workspace.The lumped parameter models presented in this work require empirical modelcalibration and validation. The success of both, calibration and validation, dependson the availability of the right measurement instruments, as these need to be ableto capture the actual positioning accuracy of machinery. This thesis focuses on theimportance of measurement instruments in industry and metrology and creates acatalogue of requirements and trends to identify the features of the measurementinstruments required for the factories of the future. These novel measurement instrumentsshall be able to improve model calibration and validation for an improvedoverall equipment effectiveness, improved product quality, reduced costs, improvedsafety and sustainability as a result of physics-based modelling and measurementof advanced manufacturing machinery.

<p> This thesis is an investigation of some of the aspects of costing and machining that are applicable to numerically controlled (N/C) machine tools with particular reference to the facilities at McMaster University,and is divided into two sections. </p> <p> Section A is a brief discussion of the suitability of N/C for simulation methods and a review of the principles of metal cutting and the problems involved in estimating costs. A method is devised to simulate the machining of "typical" parts that have been generated by a random strategy. The results of the simulation were used to find a relationship between the geometric parameters of each part and the time required for all the machining operations to make that part, this relationship was called the "complexity factor" for the part. Sugestions for possible future extensions to the work were made.</p> <p> Section B is a feasibility study for increasing the range of use of a Moog point-to-point N/C machine to contouring, using the computer facilities available at McMaster University. It was proposed to produce a numerical control tape to machine a general oval based on a method of approximate linear interpolations using an on-line, time sharing computer terminal and a PDP "mini computer". The contouring method was tested by machining a circular groove (an oval with equal major and minor axes) and measuring the accuracy. The possibility of extending the work to other contours and three dimensional solids is discussed.</p> / Thesis / Master of Engineering (MEngr)

The traditional product development process has been sequential in nature, with the product going through design, process planning, manufacturing and assembly. This sequential decision making results in increased costs and higher product development times. With the trend towards better product quality, product customization, shorter product life cycle, and international competition, manufacturers are faced with the challenge of improving product quality while reducing product development time, manufacturing lead-time, and product cost. To cope with these challenges, the product development process has to be made more efficient by integrating manufacturing and assembly considerations in the design phase itself, through the use of techniques such as Design For Manufacturability (DFM) and Design For Assembly (DFA). DFM techniques have to be automated to take advantage of the vast advances in CAD and CAM systems. However, the automation of DFM has been constrained, especially for machined components, by the lack of methodologies which are dependent on the process of manufacture, and the incomplete part data representation in CAD systems. This research created a DFM methodology for machined components, along with an appropriate data representation scheme. Also, a software prototype was developed to demonstrate and validate both the methodology and the data structure. The DFM methodology consists of three modules: DFM feasibility, process plan generation, and DFM analysis. The DFM feasibility module performs an initial feasibility check on the material, dimensions, tolerances, and configuration of the part. It also generates the spatial relationships between features. The process plan generation module uses a sequence identifier algorithm to generate the manufacturing sequence. The DFM analysis module evaluates tolerances relative to their stacking effects and manufacturability. It then analyzes the part configuration for possible design and process plan improvements. A software prototype was developed using C++. It addresses the dimension checking, tolerance checking, configuration checking and spatial relationships generation in the DFM feasibility module. In the process plan generation module, the sequence of surfaces/features to be generated has been automated. This sequence is one of the major inputs to a computer-aided process planning module. Other methodologies for non-machined components can be easily integrated into the DFM framework for complete automation of DFM analysis. / Ph. D.

Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1981 / Includes bibliographical references. / by Clinton Sebastian Stanovsky. / M.S. / M.S. Massachusetts Institute of Technology, Department of Mechanical Engineering