Study on the function surface-based Growth Design theory of conceptual structure

Conceptual structure design is the key issue of mechanical product design. Growth Design is proposed for mechanical conceptual structure design by referring to the growth mechanism of organism in this paper. The theoretical foundation for the Growth Design, such as Generalized Positioning Principle, Function Surface and Function Pattern are introduced firstly. The process of Growth Design is presented based on the decomposition of Function Surface, and the main growth step is introduced, including the creating of product prototype, the growth based on the decomposition of Function Surfaces and the matching from conceptual product to entity product. Then, the main decomposition strategy of function surface is proposed, and it points out that the decomposition of Function Surface should follow the rule: the assembly complexity and manufacturing complexity of the product should get optimal allocation based on all function requirements being met. Finally, the degree of similarity is proposed for the matching from conceptual product to entity product. The product case base is established with three levels: Function Pattern, Shell product and Entity product, and the coding rule of case base are presented too. The design process of a vise fixture as an example is given to demonstrate the effectiveness of the design theory.