Study On Function Decomposition And Behavior Consistency Under Function-form By Direction Creative Design Model

This paper is about mechanical symbol scheme creative design. For overcoming the shortage of conceptual design based on the Function-Behavior-Structure (FBS) model in obtaining the creative conceptual design results, function cell is decomposed into basic operation. The basic operation is expressed by basic motion behavior. Our research is under taken by National Science Foundation Class, named "Support Function-Structure double Creativity in Electromechanical Product Computer Aided Design". The method based on knowledge modeling,expressing and utilize. By this paper, the process of functional decomposition is expressed with the quotient space(X,f,T)theory mathematically. Under quotient space, X represent the discourse domain of different layer functions from function decomposition,f express the property of function, and the T record the connect relationship of functions, the hierarchical model of function decomposition is established. In the model, function is decomposed into basic operation actions. After basic operation, divided from function, mapping into structure behavior, the fuzzy clustering is introduced into analysis the consistency of behavior from function layer, the behavior relation and the behavior interface. Then, prospose a correlation analysis approach for behavior elements. The fuzzy clustering algorithm was introduced to converge behavior's elements. At last, compare the sequence between the result and the behavior from function layer.In order to support function behavior double creativity, a database is founded. In the knowledge-based model, the definition of basic operations is given and it expressed basic structures. In this model, the input and output property, Type of behavior and behavioral characteristics is described. The model also considers the basic structure's multi-functional characteristics.At last, based on the above researches, try to develop a mechanical symbol scheme design prototype system. The software is mainly composed of knowledge database,function decomposition, behavior structure changing and symbol scheme obtaining. Through this sofeware, designer can get creative symbol scheme.