Numerical simulation method of thermal analysis for bridges without using field measurements

Structural temperatures have significantly negative effects on the performances of bridges. In this study, a numerical method of thermal analysis for bridges without using field measurements is proposed and investigated based on a long-span suspension bridge under weather conditions of a sunny day. Firstly, basic theory and methods of bridge thermal analysis are discussed. Secondly, the long-span suspension bridge and the structural health monitoring system are briefly introduced. Then, the finite element model of a typical section of the box girder of the long-span suspension bridge is constructed for transient thermal analysis to calculate the temperature variation and distributions. The thermal boundary conditions are calculated using the meteorological information from the nearby airport rather than the field measurements for thermal analysis. At last, the thermal boundary conditions are applied on the FF model to obtain the structural temperatures using transient thermal analysis. Besides, the conventional method using the bridge field meteorological measurements is also carried out for comparison. All the simulated results of structural temperatures are compared with the field measurements. All of them have good agreements. It is demonstrated that the proposed method is reliable and effective.