FEATURE-BASED DESIGN BY VOLUMETRIC MACHINING FEATURES

Substantial research efforts have been spent on feature applications t owards the integration of CAD and downstream manufacturing functions s uch as process planning. However, the majority of contemporary feature -based systems cannot handle the interactions of features in practical applications. Feature interactions cause problems in feature recognit ion as well as feature-based design systems. This paper presents an ap proach to represent and analyse features in a feature-based design sys tem. In this system, a part is modelled by volumetric machining featur es, which are then decomposed into air volumes and material volumes. G eometric reasoning is used to evaluate and analyse the features increm entally during the design stage. Feature interactions are detected by the possible interactions among material volumes. Several interacted o r face-contacted material volumes can be clustered into a single-mater ial volume. For each material volume, a tool-swept volume is generated to represent the space to be removed in the machining process. The co mplete feature instancing process is governed by the validation rules to ensure that the part is manufacturable.