Despite criticisms of its methodology, the Taguchi philosophy for quality improvement is generally applauded. Though originally intended to primarily achieve its results "off line", during the product design phase and before manufacturing, it has frequently also been deployed to solve problems "on line". Taguchi identifies the crucial design phases as "system design" and "parameter design", and his statistically-based tools are directed at the latter. The general objective of this investigation is to study two contrasting approaches to product and process optimisation, ie Genetic Algorithms, which may be appropriate to both "system design" and "parameter design" phases, with Taguchi and related statistical tools which may be appropriate to the "parameter design" phase. The literature review concentrates on the up and downsides of Taguchi Methods, focusing on the philosophy and methodologies. Its statistical content, particularly related to the use of Signal-To-Noise ratios and saturated fractional factorial designs, have widely reported deficiencies. In order to evaluate and, if necessary, overcome these deficiencies, a combination of Taguchi and non- Taguchi tools are brought into an experimentation strategy to determine robust methodologies that contribute to enhanced product performance. The approach is motivated from a design for quality standpoint and is directed principally at improving performance. The approach is illustrated using three case studies in surface finish from metal cutting and simulation systems optimisation. These case studies involve a variety of experiments different in nature, from real physical experiments to computer-based ones, and tackling a wide range of different problems such as: surface finish in milling and turning machining (metal cutting), optimum travel time and traffic junction control (transport traffic simulator) and out-of-balanceforce problem (optimisation of simple Genetic Algorithms). The study of Taguchi tools is an extension of previous work by Taher (1995). Some of his investigations are extended, principally the reliability of Taguchi saturated fractional factorial arrays, the need for factor/level analysis, criticisms of the Taguchi Signal-to-Noise ratios and the use of sequential experimentation. In addition to these, attention is focussed on the use of repetitions within the Taguchi methodology, the use of transformations or Generalised linear Models and the possibility of using robust statistics. The adoption of a sequential experimentation approach leads to a successful use of predefined Taguchi arrays influenced by user knowledge of confounding and interaction effects on main factors. From a global viewpoint, Factor/Level analysis is highly recommended. It is also determined that the reliability of results is highly affected by the use of Signal-to-Noise ratios, and alternative dispersion control tools are strongly advised. Taguchi's robust design methodologies are of value but require integration with other design and quality assurance methodologies, such as Concurrent Engineering and Quality Function Deployment. The optimisation of a simple Genetic Algorithm (for the out-of-balanceforce problem) is used as one test case for the investigation of Taguchi tools. However, this investigation is itself of interest for the general use of genetic algorithms as it addresses issues such as appropriate population size and choices for crossover and mutation modes and probabilities. Many previous investigations of these have only been of the "one factor at a time" type.

Thesis (PhD in Metallurgical Engineering)--University of South Australia, 1996

Thesis (PhD in Metallurgical Engineering)--University of South Australia, 1996

Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references (p. 149-156). Also available via World Wide Web.

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: 4 l. at end.

Thesis (Ph. D.)--McMaster University, 2003. / Advisor: Mohamed Elbestawi. Also available via World Wide Web.

Tool wear is a significant problem for manufacturing companies and represents a major challenge in their operations, but it is also a way they can gain a competitive advantage. To do this it is important to set up a standard procedure to develop high performing tooling. This thesis outlines how the Finite Element (FE) method can be used to understand and develop tool geometry. FE based simulation, as a numerical method, is a reliable method to assess the performance of a cutting tool before conducting machining tests based on the force and temperature profile predicted by the FE model. Defining a mathematical model which can be used as a built-in algorithm for tool wear prediction is very challenging and time consuming. Instead there is a possibility of using other factors such as stress distribution and temperature profile and correlate them to tool wear. In this research, the performance of different tool edge radius in cutting has been studied through experiments and in parallel Updated Lagrangian Models have been developed through ABAQUS/EXPLICIT for various cutting conditions, and experimental data was used to validate the data that has been generated from the finite element models. These models are very convenient to develop and capable of being applied for other types of material and cutting conditions. Thus, they represent an efficient way to reduce the amount of experiments needed to improve a tooling, the machining process, and thereby provide an effective way to increase the machining productivity of manufacturing companies. / Thesis / Master of Applied Science (MASc)

Thesis (M.S.)--Mississippi State University. Department of Mechanical Engineering. / Title from title screen. Includes bibliographical references.

Metal cutting is an important process used to manufacture components with machined surfaces or holes. Due to the wide usage o f this manufacturing process, research with the aim to optimize the cutting processes is important. Improving cutting techniques even mild)s can result in major cost savings in high volume production. Better machining practices will result in products of better precision and of greater useful life . Benefits can also be had from increasing the rate of production and producing a bigger variety of .. products with the tools available. The area of metal cutting has been researched widely by people like Tourrett, Taylor, Cohen, Davis and many others to find improved techniques and methods. This project was conducted to improve cutting conditions by ensuring that the tool geometry is always optimal . The effect of tool geometry on cutting performance has been discussed in detail by many researchers, but the practical application of these theories is an area that needs further attention. For this project a device was developed to vary the tool geometry with stepper motors on command from the controller. This device was used for research into the viability of varying tool geometry during machining to obtain different cutting conditions. Stepper motors ensure high accuracy in the control of tool geometries. The ease of controlling stepper motors, also simplified the controlling program and communication devices a lot. Rotating the stepper motors results in rotation o f the tool holder around the tool tip. Tool angles are varied without affecting the other cutting parameters like the depth o f cut, metal removal rate and cutting speed. With these cutting parameters staying the same, the change in tool geometry should result in a change in the power consumed during cutting and the force required for cutting . Other measurements for cutting performance like temperature of the tool and workpiece and the acoustic print of the tool will also change. Results prove that cutting force measurement can be used effectively to measure the optimal cutting conditions . The back rake angles and side rake angles have the biggest influence of all the tool angles on metal cutting . This is demonstrated by a number of researchers [28] as discussed in section 2 . 2. This thesis proves how the on-line changing of tool geometry, ensures the optimal cutting conditions. / Thesis (Ph.D.-Mechanical Engineering)-University of Natal, 1996.

This thesis presents the simulation of chip formation in orthogonal metal cutting to evaluate the predictive capabilities of finite element code DYNA 3D. The Johnson and Cook constitutive model for materials, OFHC Copper, Aluminum 2024 T351, and Aluminum 6061 T6 alloy were incorporated into the simulation to account for the effects of strain hardening, strain rate hardening, and thermal softening effects during machining. Calculated values for the Johnson and Cook constitutive constants for Aluminum 6061 T6 alloy were determined from the literature. The model was compared to experimentally measured shear angles, chip thickness, chip velocity, and forces from the literature to evaluate the accuracy of the finite element code for a range machining strain rates. In an attempt to determine the predictive capabilities of DYNA 3D a strain rate regime of 10+3 s-1 to 10+4 s-1 was defined as the optimal strain rate regime for the orthogonal metal cutting application.