Numerical feasibility study of fabric formwork and its supporting system for a reinforced concrete saddle shell

The paper presents the numerical modeling and analysis of a form found 10 m span concrete saddle shape thin shell. The shell design corresponds to a purely axially loaded shell under gravity loads; any bending action is eliminated. This shape results from a numerical form-finding procedure based on the force-density method. The principle of the methodology, namely finding a catenary shape, relies on the well-known hanging models of Heinz Isler. In the presented form finding methodology the continuous shell is firstly modelled as a hanging chain model with no bending stiffness or compression capacity. By doing so, any shear stiffness acting in the continuous shell, is ignored. The shape is then inverted to a compression form. The resulting grid shape is modelled as a continuous shell in the Finite Element Analysis program Ansys in order to study the load-carrying behaviour, the deformations and the stability under loading combinations conform the Eurocodes.

Publication year:2010

Keywords:form finding, compression shell, textile formwork