Case retrieval in body-in-white parts based on similarities of welding and assembly process

To make full use of previous successful process experience,a case retrieval methodology for body-in-white parts was proposed,which was based on the similarities of welding and assembly process.Firstly,by considering the primary features,the secondary features and the feature constraint relationships,a feature information model for parts was established.Secondly,from the view of the process similarity,the similarity was calculated by three stages analysis between a new part and old part in the case library.In the first stage,both the shape and the relationship similarities of the primary features and secondary features of the new case and old ones were calculated respectively.Many old cases with little similarity in shape were removed.In the second stage,the geometric similarities were calculated.The old cases with more difference in size were removed.In the third stage,similarities of the material type and the material thickness were calculated.The most similar case was retrieved.Finally,a case study indicated the effectiveness of this method.