The paper presents the results of failure experiments and an elasto-plastic analysis of free-formed shells. The shapes of free-formed shells were obtained by numerical form finding process. The six models with different tie-beam stiffness and different rises were tested, and the results of some of them were compared with analytical results. These analytical results show the good agreement with the test results. And these results indicate that the stiffness of the free-formed reinforced concrete shells are considerably affected by the support condition and rise-span ratio, but the effects of these factors are not clear in the load carrying capacity of the shells.
