CAD-integrated design and analysis of shell and membrane structures

A better integration of design and analysis, also referred to as CAD-CAE-integration is an ongoing challenge. Although important progress has been made in terms of automated mesh-generation or concerning the use of the same basis functions for both design and analysis, a full and consistent integration has not yet been realized. On the other hand side, the design of mechanically motivated structures like architectural membranes and shells requires a close interaction of design and analysis. The present contribution presents the realization of a concept that allows extending a CAD-environment consistently with the ability for structural analysis. In most of today’s CAD systems the geometry is described using the so-called boundary representation (B-Rep). Based on this B-Rep description, the Isogeometric B-Rep Analysis (IBRA) has been developed in order to perform mechanical simulations directly on a CAD model without the need for separate models. Within IBRA geometry manipulations like trimming or coupling can directly be interpreted based on newly introduced B-Rep elements. Arbitrary geometries can be assigned a mechanical property as basis for a structural analysis. The integration of the IBRA-approach in a CAD-environment is exemplarily realized for the structural analysis of architectural membranes and shells within the NURBS-based software Rhinoceros 5. A fully integrated plugin called “TeDA” enables enriching the CAD-model with the necessary properties to perform form-finding and structural analyses directly within Rhino 5, including the integration of various boundary conditions or loading scenarios. The consistent treatment of the geometry enables the analysis of hybrid structures and recent challenges like active bending. Throughout the whole analysis process, the geometry stays intact. By using the same model, any change in the design is automatically included in the analysis. The mechanical and theoretical background as well as the concept’s capabilities will be presented. Selected examples of challenging applications will visualize its potential.     «

A better integration of design and analysis, also referred to as CAD-CAE-integration is an ongoing challenge. Although important progress has been made in terms of automated mesh-generation or concerning the use of the same basis functions for both design and analysis, a full and consistent integration has not yet been realized. On the other hand side, the design of mechanically motivated structures like architectural membranes and shells requires a close interaction...     »