An integrated design and planning environment for welding: Part 1: Product modelling

There is extensive literature and industrial evidence that the early stages of product design are particularly important for life-cycle cost control, product quality and manufacturability. The early stages of weld structure design are characterised by the gradual generation and addition of information to a generally incomplete product model. This process includes the identification of component shapes, positions of joints between components and the selection of joining methods, based on the required functionality and applied manufacturing constraints. Aggregate process planning is a methodology for evaluating alternative design and processing options at the early design stages by applying manufacturing process criteria. This paper discusses the definition and implementation of CAPABLE/Welding, a newly developed aggregate process planning system for supporting early design assessment of complex fabrications. The first part of this paper details the overall structure of the aggregate product model implemented in CAPABLE/Welding. An aggregate product model of a fabrication is defined using object-oriented and feature-based methods. The use of relevant design rules to generate weld features is discussed in this paper using as an example the design procedure for a complex fabrication. Methods for abstracting necessary product data from STEP files and directly from a proprietary CAD system are also discussed. The second part of this paper discusses how the product model can be used in aggregate process planning.