Geometric Models in Mechanical Design

The rise of solid modeling as a principal medium for mechanical product description can be traced to the requirement of informational completeness of geometric representations Unfortunately traditional geometrybased systems do not contain important information needed for many engineering activities and tend to force costly iterations in a product development cycle We seek to understand spatial proper ties and combinatorial structure of mechanical parts in terms of simple interacting constructs related to part functionality and manufacturing processes Existence of such a structure is illustrated for a simple part that is characterized in terms of its kinematics strength spatial containment and manufacturing characteristics The resulting explicit representation of correspondence between mechanical characteris tics and spatial elements allows systematic product development ecient modication procedures and rational tolerancing approaches eliminating many costly errors and iterations in a product development cycle The study also highlights the lack of and the need for formal models supporting systematic design process in Proceedings of the th IFIP WG Workshop on Geometric Modeling in CAD Ma