Model updating and variability analysis of modal parameters for super high‐rise structure

Summary For Structural Health Monitoring (SHM), a core prerequisite is to accurately identify the modal properties. Since the dynamic characteristics of a structure change under the effects of different environmental factors such as temperature and wind, it is necessary to determine how the environmental factors affect the modal properties. This study focuses on the Guangzhou new TV tower (GNTVT), which is a 610‐m high structure. Based on the measured data from GNTVT, both the varying patterns of the operational modal parameters under the effects of different environmental factors and the Finite Element Model (FEM) updating based on Genetic Algorithm (GA) had been investigated. Then, using the updated FEM, the effect of the temperature on the modal frequency had been investigated under two situations: (1) Temperature only affects the modulus of elasticity. This situation was considered to be more important because of the significant frequency change. When temperature increases by10°C, the maximum change of modal frequencies is 1%. (2) Temperature only affects the geometric stiffness of structure. This situation was considered to be less important because the change in the frequency is very small which may be ignored. When temperature increases by10°C, the maximum change of modal frequencies is 0.02%. The simulated results were consistent with the measured results.