Low Cost Double Curvature – Exploratory Computational Modelling, FE-analysis and Prototyping of Cold-Bent Glass

Abstract

The fabrication of projects with complex geometries often implies a significant waste of material, since custom molds need to be created and irregular shapes need to be cut out of larger sized elements. For low curvatures, cold elastic bending processes can be applied. However, elastic bending techniques have mainly been utilized to create simple curvature panels for architectural projects. This paper explores computational simulation in relation to a digitally controlled fabrication method of bending rectangular glass sheets elastically into irregular double curvature. This is done through exploratory prototyping within the framework of a Master of Science course on digital production, and additional computational modeling and FE-analysis. We used algorithmic real-time simulation to approximate the bending process of cold-bent glass and elaborated on details of the simulation process and possible surface types and curvatures. Our empirical tests on simply curved, ruled and doubly curved surface types used float glass as well as heat-treated glass. A detailing system was developed to clamp the glass panels into position. We evaluated the results of the computational simulation (Rhino with plug-ins) as well as FE-Analysis (Strand 7) and compared the resulting geometries to the measurements of the physical prototypes. In order to demonstrate the system’s capacities on a larger multi-panel geometry, we constructed a 5m x 4m prototype of a doubly-curved glass surface.