Research On Key Technology Of Computer Aid Product Design Oriented Maintenance

Maintainability is one of the basic product design attributes. It indicates the difficulty and economics of product maintenance. Improving product s maintainability can greatly enhance system productivity and lower product life-cycle cost. Therefore carrying out effective maintainability design and evaluation is important.Aiming at maintainability design and evaluation of products, related research works on maintainability design and evaluation factors are thoroughly reviewed, such as maintainability evaluation analysis methods, product modeling for maintenance and maintainability analysis software. Out of what have been reviewed, this work focuses on research and development of identifying maintainability evaluation factors, methods of evaluation and prototype integration techniques. The main contents of this thesis are summarized as follows:(1) The tribo-maintainability related design factors are analyzed from systematic perspective and a more complete set of six factors are concluded. A fuzzy set based approach is then developed to quantitatively evaluate the combined effect of six factors for tribo-maintainability of a design.(2) A novel connector-knowledge based approach is presented for automatic generation of standard connector related disassembly precedence constraints. By integrating this novel knowledge based reasoning (KR) with geometric reasoning (GR) approaches, both approaches are utilized to their best advantages. Necessary disassembly constraint information can be automatically generated with less computational complexity.(3) Base on the above-mentioned theoretical works, maintainability evaluation prototype system (MEPS) is designed and developed on UG platform. The system contains two key modules: the tribo-maintainability factors evaluating module FTE, and disassembly maintainability factors evaluating module DCM. Through this CAD integration, at design stage of the product life cycle, it is more practical for designers to evaluate different design solutions for their tribo-maintainability and disassembly properties so as to reduce time and cost needed for maintenance.(4) A case study is conducted with a common assembly of a gear reducer. The result has demonstrated the proposed methods and the prototype developed for their effectiveness.