Abstract: Aiming at difficultly sorting and retrieving shaft assemblies, a shaft assembly retrieval method based on structure similarity is presented. The connecting of mating surfaces between components is abstracted as assembly joint, assembly place constraint and qualitative geometrical constraint are introduced to describe the geometrical relation between assembly joint elements. Assemblies are divided into substructures and the connection relations between functional surfaces in same component, which are contained in different substructures, are introduced to describe connection relations between the substructures. The assembly structure model is built on the basis of assembly connection graph and substructure connection graph respectively. The method of dividing shaft assemblies into substructures is discussed. Branches in an assembly connection graph and a substructure connection graph are specified by enclosing them in parentheses, cyclic structures are represented by breaking one connection relation in each ring, in this way, the structure of a shaft assembly can be represented by a linear sequence of letters and digits. By referring to the linear sequence for compounds in chemical database, a structure coding method is presented. The structure retrieval mechanism of shaft assembly is presented. The method is validated by taking shaft assemblies of bevel gear cantilever support as example.

Key words: Shaft assembly, Shaft assembly structure, Similar assembly retrieval, Non-linear and non-steady, Prediction, UniTire, Tire model