Laboratory of Digital Models in Structures and Construction

Digital Twinning of doubly-curved surfaces

An Industrial Doctoral Program from AGAUR, the Catalan funding body allowed the laboratory to expand its capabilities by leveraging knowledge from the Industry and Academia. The topic of the program is Doubly-Curved Surfaces and their Twins. Catalan and Gaussian vaults were established as case studies during the development of research and innovation actions on those heritage structural elements.

Digital twinning of the built environment, supported by Building Information Modelling (BIM), presumes a thorough integration of structural elements into a broader digital ecosystem. By linking data related to geometries, simulations of physical behavior, construction logistics, and other relevant real-world information, digital twinning enables tracking structural elements across their life cycle.

The laboratory contributed to this project by developing a procedure for digitally twinning these two doubly-curved structural elements: the Catalan and the Gaussian vaults. This twinning process relied on defining digital replicas of these vaults according to the Industry Foundation Classes (IFC) schema, which provides a framework for describing diverse geometries.

This work is particularly relevant in Catalonia, where these doubly-curved vaults hold significant architectural value.

Geometries

The vaults achieves efficiency by relying on this curved geometry to distribute the forces. While Catalan vaults focus on compression, Gaussian vaults can respond to a variety of structural forces (compression and tension). A digital representation of such elements based on Ifc is developed throughout the project.

 

Measurements

The vaults' dynamic behavior was analyzed through sensor-based measurements, capturing structural responses. Simultaneously, their geometric characteristics were assessed using point cloud data (photogrammetry and laser scanner),  enabling precise shape reconstruction and deformation analysis.

Advanced BReps

Advanced Breps in the IFC schema are suitable due to their capability to handle intricate geometries with precision. Advanced BReps support NURBS-based surfaces and curves, which are essential for capturing the smooth transitions and irregular shapes found in architectural vaults. The project allowed extending MatchFEM capabilities to deal with geometries of such complexity. 

 

Material ontology

The vaults are characterized by their construction using thin tiles or bricks, usually laid flat in several layers with fast-setting mortar, such as gypsum or lime mortar. In BIM, specifying a constituent set for materials is essential when dealing with masonry, in this case, of bricks and mortar. The projet allowed the lab to explore new ways of organizing material information with a set of ontologies.