Study on prestress distribution and structural performance of heptagonal six-five-strut alternated cable dome with inner hole

The cable dome structure is a highly efficient prestressed space structure with reasonable force, attractive shape, and large spanning capacity. It is increasingly widely used in stadiums, exhibition halls, terminals, and other large-scale public buildings and the roof structure of various transport hub projects. To solve the problem of weak overall structural stability of the traditional cable dome structure, a new type of prestressed space structure is proposed - heptagonal six-five-strut alternated cable dome with an inner hole. The composition of the structural system was given and a theoretical study of the distribution of structural prestress was carried out; based on the symmetry and periodicity conditions, the initial prestress distribution of the structure was accurately calculated using the node balance method, and the formulae for the geometric parameters of the structural cable-strut were derived; the numerical model was established by using the finite element software ANSYS 2022 R1, and the force characteristics of the structure under full-span uniform load, half span uniform live load, wind load, and temperature were studied. The effects of structural prestress, overall shape, and support stiffness, totaling three categories and six parameters, on the structural mechanical performance of the internal force of the member, node displacement, and support reaction force were analysed in detail and the sensitivity of the parameters is assessed quantitatively, accordingly, the values of the main design parameters such as thick-span ratio are given as suggestions. The analysis results show that the new structural system has a high load-carrying capacity and deformation resistance, and its proposal provides a new scheme and new ideas for the selection and design of the cable dome.