A PROPOSAL OF STRUCTURE FOR A VARIATIONAL MODELER BASED ON FUNCTIONAL SPECIFICATIONS

摘要

For several years, CAD software have adopted a variational approach for modelling. This choice is justified by users' needs. Indeed, a product is often designed to fulfill requirements that are not expressed as geometric specifications. In addition, the geometric model of the product evolves continuously during the design process. During this process, the software must be able to preserve the coherence of the model specifications. To fit into this context, a variational modeler has been set up which includes new concepts of analysis and solving approaches to identify locally over/under-constrained systems and provide more feed back to the designer. The structure of the modeler is briefly outlined followed by the introduction of the analysis and solving modules that are clustered into three tasks: a pre-solver analysis, a solver, a post-solver analysis in case of resolution failure. Parts of examples are used to illustrate the descriptions of this structure.