Beijing Building Construction Research Institute CO., LTD
Science and technology new star program of Beijing science and Technology Commission（Z14110601814085）；Science and technology program of the Ministry of housing and urban and rural construction（2016-R2-043）。
Through the modal analysis and test of the 1:10 scale model of 60m circular spoke cable-trusses, the influence of 3 parameters of cable prestress, rise to span ratio and diameter ratio of inner and outer ring on the natural vibration characteristics of the structure were investigated. The results of test and theoretical of the first four order modal were compared and analyzed. It can be seen that: The first, second order vibration modes of the structure are antisymmetric upper and lower vibrations, the third order is the inner ring torsional vibration, and the fourth order is the relative torsional vibration of the inner ring. The frequency error is less than 10%, and the experimental mode of vibration is in agreement with the theoretical mode. The frequencies of the first four modes are all above 10Hz, indicating that the spoke cable truss structure is of low frequency dynamic response, and the natural frequency is small and the distribution is dense. When prestress level of the structure is higher, the modal frequency will increase, and the stiffness will also increase. With the increase of sagittal height, the structural frequency will decrease, and the structure is more prone to lateral instability. With the increase of the inner and outer ring diameter ratio, the torsion stiffness of structure will decrease and torsion instability will also occur.