In 1989, Shapiro and Voelcker introduced three principles for relating shape and function with the goal of establishing an appropriate formal role for geometry in a theory of mechanical design. This technical note contributes to the establishment of such a theory by using an example from their technical note to illustrate the potential value of incorporating shape embedding, used in the shape computation and shape grammar community to support shape synthesis, into CAD packages that are used primarily to support shape definition and analysis.

Design configurations, such as Bills of Materials (BoMs), are indispensable parts of any product development process and integral to the design descriptions stored in proprietary Computer Aided Design and Product Lifecycle Management systems. Engineers use BoMs and other design configurations as lenses to repurpose design descriptions for specific purposes. For this reason, multiple BoMs typically occur in any given product development process. For example, an engineering BoM may be used to define a configuration that best supports a design activity whereas a manufacturing BoM may be used to define the configuration of parts that best supports a manufacturing process. Current practice for the definition of BoMs involves the use of indented parts lists and dendograms that are prone to error because it is easy to create discrepancies across BoMs that, in essence, are defined through collections of part identifiers such as names and part numbers. Such errors have a significant detrimental effect on the performance of product development processes by creating the need for rework, adding costs and increasing time to market. This paper introduces a design description capability that ensures consistency across BoMs for a given design. A boolean hypercube lattice is used to define a design configuration space that includes all possible configurations for a given design description. Valid operations within the space are governed by the mathematics of hypercube lattices. The design description capability is demonstrated through an early engineering design configuration software tool that offers significant benefits by ensuring consistency across the BoMs for a given design. The software uses and generates design descriptions that are exported from and imported to commercially available design systems through a standard (ISO 10303-214) interface format. In this way, potential for early impact on industry practice is high.

IT support for engineering involves the integration of existing, evolving and future product data, and software that processes that data. Thus, there is increasing interest in the representation of product data in the computer to support CAE applications. To avoid duplication and inconsistency, and to support the use of new implementation technology as it emerges, conceptual models of product data are required. Such models are independent of the software and hardware environments in which they are implemented. System architectures to support the integration of applications at implementation time are becoming an accepted part of engineering information systems. To use these software support environments effectively, integrated product data is required. It must also be possible to extend the integrated product data in a controlled fashion if it is to evolve to support future engineering applications effectively. A framework that is a part of the product data at the conceptual modeling stage helps to satisfy these requirements. The framework presented is a structure for the information content of product data rather than for the implementation of such data. Product data based on the framework can be successfully implemented in a number of different database forms. This paper describes a framework for electromechanical product data that has been implemented in a structure editor and is being used to support a range of engineering applications. The process of product data integration can be improved by using existing integration strategies together with a framework that provides an overall organization for the data.

A novel algorithm for automatic finite-element mesh generation is described.It uses constructive solid geometry to provide the geometric data for the object to be meshed.The geometric definition of the object and a value for the required mesh density are the only inputs.The method consists of two stages: point generation and mesh construction over the points.It has been implemented in two dimensions and is capable of generating predominantly "good" quadrilateral elements.Triangular elements are only created in circumstances under which quadrilateral elements are not feasible.