Research And Application Of Modular Design For Mechanical Products Based On Extension Theory

Module design, as one of the most important design methods for machinery products development and innovation design, has attracted deep attention from enterprises which are characterized by short design period and quick adaption to market demand. Extenics, a kind of formalized module research object extension using for solving contradictory issue among objects, aims to provide a kind of formalized knowledge description approach and modular contradictory issue solving methods. This article proverbs into key technologies such as module division and allocation under the process of machinery products modular design by introducing axiomatic design theory and extension theory, and those research were validated with examples.First of all, unit theory is introduced with the combination of unit theory and traditional knowledge representation methods regarding lack of proper knowledge representation for different kinds of design information during the machinery products’ module design. Secondly, this article put forward to module division approach based on axiomatic design and clustering through the current study on module division methods. This method applies axiomatic design of mechanical products for a top-down decomposition and gains its structure module through “Z” type map. Based on decomposition module, an analysis related to module is done from the aspects of function, structure, connection ports and other reverse sides. Products layer module division is archived by utilizing hierarchical clustering method and a top-down decomposition in sub-modules. The essay puts forward to a calculation method basing on a kind of improving extension distance similarity and makes existed module example appliable into new products development according to the difference of module types in terms of weakness of module search and module modification during modularized design process. In terms of conflicts between functional requirement and design structure for products design, solution module for extenics incompatible issues is introduced and function of consistency degree for extension module modification is given which aims to judge if design goal and design condition are compatible. Then machinery products’ extension module allocation module based on similar module reusing are established. At last, on the basis of above-mentioned theory, the article finishes development of water turbine module design system and gives example of system operating through founding system structure of water turbine module design system and analyzing system’s main function module and operation process.