ABSTRACT
The dynamic properties of long-span suspension bridges were studied based on fine temperature effect analysis and thermal-eigenvalue problem. The heat transfer between structure and surrounding air was related to wind speed, atmospheric environment and thermal properties of ground surface. Temperature variations in cables and uneven heat transfer coefficients on the pylon were obtained with multi-scale modeling and CFD (Computational Fluid Dynamics) method, respectively. Then, based on the fine temperature distribution, the effect of temperature variations, temperature gradient and material properties on the structural dynamic properties were comparatively analyzed in different seasons. Consistent with other researches, an overall decrease in modal frequency was observed with the increase in temperature. Bur for long-span suspension bridges, the dynamic properties were mainly caused by the thermal stress and the corresponding deformations. The novelty of this work lies in the accurate description of the thermal gradient field, as well as the refined mechanical representation of time-varying thermo-dynamic properties for suspended-cable structures.
