Feature based modeling shell: Design and implementation

Contemporary geometric modelers are unsuitable for mechanical design because of mismatch in abstraction level. The database of these modelers cannot be used to drive automated applications such as engineering analysis or process planning because of missing product information. In this paper we give an outline of an integrated system for design and applications; the system reasons in terms of form features. Object oriented programming techniques support user definition of form feature (volumetric shapes) that may be positioned and manipulated in a logical manner. A solid modeler interface generates equivalent solid representations in parallel with feature representations. Mechanisms for parameter inheritance and validity checking (cognition) are also discussed. The system is modular which will allow integrating it with tolerance and material modelers that are currently under development. AI techniques have been applied to solid modeling resulting in this powerful feature technology for creating very flexible and integrated CAD systems for the next generation engineering tools.