Research On The Propagation Path Of Function Change In Product Conceptual Design

Product design is a process to find the best physical structure when function contradicts with design environment. In product lifecycle, the design change will be caused because of the difference between use environment and design environment. Due to the close relationship between function and structure, function and function, structure and structure, and different sub-systems, chain reaction will happen when design is changed.In this paper, to solve the problem of propagation path is changed caused by part function change in conceptual design, a method to solve propagation path of function change in conceptual design was proposed based on engineering change theory. The main research contents are shown as follows:(1) Product information model of function principle component-behavior- function(S-B-F) was established according to reverse mapping from structure to behavior, then to function. Firstly, based on product design information, structure layer of information model was established according to connection relationship among structures(structure is the final result in concept design, and it’s the early carrier to achieve function and behavior). Secondly,behavior structure was established based on the information about action state and static behavior. Thirdly, function structure was established through solving mapping from behavior to function and analyzing total function.(2) Analysis on solving propagation path of function change. In the process of establishing product information model of S-B-F, through matching analysis on function flow between changed function and functional structure, fusion analysis on the status of input/output between change behavior and behavior structure, and the feature betweenchanged principle component and unchanged principle component, the function, behavior and structure which are influenced by function change were found. So the propagation path of function change was solved.(3) A system on solving propagation path of function change in conceptual design was developed based on the above theory. And ice crusher was taken as an example to verify its feasibility and effectiveness.In this paper, the information model of S-B-F was solved based on reverse mapping of principle component-behavior- function, then the propagation path of function change was known, and an engineering example was taken to verify its correctness. In future, more perfect information model of S-B-F can be solved by mapping behavior to function. Other factors which influence propagation path will be researched based on the model to improve this method.