The 'FROZEN FLOWER' ice project by GHENT UNIVERSITY students of civil engineering in Belgium consists
of 8 hyperbolic paraboloid shells in a radial configuration. The shape is inspired by the works of Felix Candela
(1910-1997), a Spanish-Mexican architect famous for his reinforced concrete shell structures.
The first challenge was the FORMFINDING of the inflatable, used to support the ice shell during its construction. This was done step by step by means of scale models and by computer simulations, until the right shape was found.
The following question was related to MATERIAL CHARACTERISATION. Consequently, material tests were performed to determine the compressive strength and bending strength of the ice reinforced by cellulose fibres. Also the resistance of the fabric for the formwork was tested in different directions, and experiments were performed to quantify the quality of the welded joints.
Then, the STRUCTURAL ENGINEERING was done by means of numerical simulations. In particular, the minimum thickness of the ice was calculated to provide stability of the shell, also in case of heavy wind and snow. A major difficulty here is the large amount of design uncertainties.
The next challenge was the CUTTING AND WELDING of the big balloon by the students. The membrane came in rolls of about two meters wide, so many welds were needed. The curved parts were most difficult. After a test inflation in Ghent, the inflatable was shipped by boat to Harbin.
Ultimately, the objective is to actually build a 15 m span shell with a wall thickness of only a few centimeters in about one week time. We are looking forward to it!