Rose windows: daring slender structures

The load bearing structure of rose windows is formed by spokes and tracery made by joining together slender stone elements through thin bedding layers, usually made of lead. The most significant load is from wind orthogonal to the glazed surface, but to assess structural strength it would be erroneous to model the structure as a beam network, because the junctions are quite weak. In some models the masonry of a rose window is imagined to develop a flat-arch response, so that compression-only vaulted networks can be generated with constitute a statically-admissible load bearing systems. Here, an alternative method is proposed, which consists in the analysis of the various elements as rigid blocks connected together by deformable joints. As a practical example, the method is applied at the rose window of a Basilica in Tuscany.