基于物元理论的任意功能树相似扩展方法

功能模型是概念设计的核心处理对象，功能树是一种典型的、应用广泛的 功能模型。使用现有相似度计算方法计算任意功能树的相似度存在困难。因此，基于布尔代 数提出了析取范式树的概念，以及两种求解析取范式树的方法，并描述了任意功能树的物元 相似度计算方法。拓展了功能树相似扩展方法的应用范围，扩大了设计解空间，增加了获得 创新解的可能性，最后给出实例验证了方法的有效性。

Method on similar extension of arbitrary function trees based onmatter-element theory

Function models are the core objects of conceptual design. Function tree is a typical function model which is widely used. Defects are found while the similarity of arbitrary function trees is calculated by existing method. Therefore, the concept of disjunctive normal form tree is proposed based on Boolean algebra. After that two solutions of Disjunctive normal form tree are presented. And a method on similarity calculation of arbitrary function trees is described. Thus, the application of function trees’ similar extension is expanded. As a result, the solution space is enlarged, and the possibility to attain innovational solutions increases. At last, an application example demonstrates the effectiveness of the method.