Robust CAD Modelling: Concepts and Principles for Industrial Applications

During product design, when many design aspects still must be understood by the design team, it is necessary to apply robust modelling approaches in order to describe the properties of the product according to the functional requirements, employing CAD system. High sensitivity to change of a CAD model can lead to unstable and unpredictable model behaviour which hinders the daily work of engineers and causes significant rework in downstream stages. Engineers need a methodology which enables them to evaluate and reduce the geometrical sensitivity of a product assembly, what the sources of variation are, their importance for the overall robustness and in what order to improve the overall design. Robustness is meant that the model structure is adjusted to react less sensitive to changes in design and model update. Robust CAD models are suitable for both downstream processes and collaboration. In this paper, we illuminate the background of CAD modelling and introduce the term robust modelling for the industrial purpose. We highlight the specific needs and expectations of the manufacturing industry. In a practical study, the application of robust modelling is shown in the design of complex machines.