Design Temperatures for Composite Concrete-Steel Girders: A-Verification of the Finite Element Model

Based on experimental records from a composite beam with a steel section and topping concrete flange, a finite element thermal analysis model was conducted and verified. The experimental beam was provided with 14 embedded and surface temperature sensors inside the concrete flange and on the steel section. The temperature records from the experimental beam were collected for two winter months. The finite element thermal model was conducted to simulate the thermal response of composite beams under the influence of open-field thermal conditions. The model solves for the conduction of heat in concrete and steel considering the different boundary conditions that include; solar radiation, reflected radiation, temperature of air and the speed of the ambient air. To verify the introduced thermal model, the predicted temperatures at the 14 thermocouples were compared with the experimental ones along the 24 hours of three days with different weather conditions. The comparisons showed that for the three days, the model could capture the temperature-time behavior accurately for all thermocouples with moderately low average absolute errors of 0.4 to 2.0 °C. Another notice was that the maximum errors in the steel section were higher than in concrete.