Does Form follow Function? Connecting Function Modelling and Geometry Modelling for Design Space Exploration

The aerospace industry, representative of industries developing complex products, faces challenges from changes in user behaviour, legislation, environmental policy. Meeting these challenges will require the development of radically new products. Radically new technologies and solutions need to be explored, investigated, and integrated into existing aerospace component architectures. The currently available design space exploration (DSE) methods, mainly based around computer-aided design (CAD) modelling, do not provide sufficient support for this exploration. These methods often lack a representation of the product’s architecture in relation to its design rationale (DR)—they do not illustrate how form follows function. Hence, relations between different functions and solutions, as well as how novel ideas relate to the legacy design, are not captured. In particular, the connection between a product’s function and the embodiment of its solution is not captured in the applied product modelling approaches, and can therefore not be used in the product development process. To alleviate this situation, this thesis presents a combined function and geometry-modelling approach with automated generation of CAD models for variant concepts. The approach builds on enhanced function means (EF-M) modelling for representation of the design space and the legacy design’s position in it. EF-M is also used to capture novel design solutions and reference them to the legacy design’s architecture. A design automation (DA) approach based on modularisation of the CAD model, which in turn is based on the functional decomposition of the product concepts, is used to capture geometric product information. A combined function-geometry object model captures the relations between functions, solutions, and geometry. This allows for CAD models of concepts based on alternative solutions to be generated. The function- and geometry-exploration (FGE) approach has been developed and tested in collaboration with an aerospace manufacturing company. A proof-of-concept tool implementing the approach has been realised. The approach has been validated for decomposition, innovation, and embodiment of new concepts in multiple studies involving three different aerospace suppliers. Application of FGE provides knowledge capture and representation, connecting the teleological and geometric aspects of the product. Furthermore, it supports the exploration of increasingly novel solutions, enabling the coverage of a wider area of the design space. The connection between the modelling domains addresses a research gap for the “integration of function architectures with CAD models”. While the FGE approach has been tested in laboratory environments as well as in applied product development projects, further development is needed to refine CAD integration and user experience and integrate additional modelling domains.