The representation of engineering systems for the building, embodiment and optimisation with standard components
Author: Hicks, Ben
Supervisor: Culley, Steve; Mullineux, Glen
Institution: University of Bath
This body of research aims to improve support for engineering design and in particular the design of machine systems from standard components. It is widely accepted that the inclusion of standard components in systems can significantly reduce cost and improve the quality of design solutions, as well as reducing time to market. Standard components play an important role in engineering design, which like many other industry sectors is now a highly competitive global market. To assist the incorporation of standard components in design solutions many suppliers and manufacturers produce electronic representations that govern the design and selection of a particular component. These representations are powerful tools for the identification and selection of individual components and significantly benefit the designer. However, the role of the designer is not just to select a range of suitable component sizes, but also to select an optimum mix of component types and sizes to deliver the desired performance characteristics, physical characteristics and quality at minimal cost. Current practices require the designer to manually evaluate many different combinations of component types and sizes in order to determine an acceptable solution. This iterative process is particularly time-consuming and analytically intensive. It is therefore highly desirable to support the designer over this process. To deliver such support a modelling approach is proposed which considers the system as a whole but also maintains the integrity of the various electronic representations necessary for the design and selection of each component. In this manner, systems of real components are dealt with. A review of modelling approaches in engineering design and computer based support tools is undertaken. It is shown that current technologies do not provide for the modelling capabilities necessary to represent systems containing standard components. As a consequence, a new modelling approach is proposed that represents the performance of mechanical systems. In the development of the new modelling approach this research has had to address six key issues; system representation, a protocol for handling interactions, system resolution, data arbitration, compatibility analysis and interfacing third party electronic representations within the modelling approach. In addition to this, two other issues are investigated that are necessary for the strategic design of systems. These are cost forecasting for systems of standard components and the issues associated with the application of optimisation techniques. The feasibility of the overall modelling approach is demonstrated through the creation of a computer based support tool which is applied to a number of industrial case studies. The research shows that it is possible to consider systems of standard components at the early stages of design and to provide for the automatic embodiment of conceptual solutions from standard components. Thereby freeing the designer's time to evaluate many more alternatives and develop a more refined design solution.