Flexural behaviour of steel panels composed of bolted modular units

Steel-concrete composite shell roofs (Comshell roofs) are formed by pouring concrete on a thin stiffened steel base shell which serves as both the permanent formwork and the tensile steel reinforcement. The thin steel base shell, constructed by bolting together open-topped modular units consisting of a base plate and surrounding edge plates, are required to carry the wet concrete loading safely during construction. The behaviour of these bolted shells is complicated by the presence of many bolted joints, so the use of finite element analysis is necessary in order to accurately predict their behaviour. For any such finite element model, the key issue is the accurate modelling of the behaviour of the bolted connections within a bolted steel base shell in which bending and membrane actions exist in both directions. In this paper, bolted flat panel specimens under transverse loading are studied to develop a good understanding of the behaviour of such bolted connections and to assess the validity of a relatively simple finite element connection model developed in a previous study. Experimental results obtained from a series of flexural tests on model bolted panels are presented together with those from finite element analyses in which the existing simplified connection model was employed. Comparisons of results from these two approaches confirm that the simplified connection model proposed in a previous study leads to accurate predictions of the flexural behaviour of these present bolted panels.