Evaluation of temperature effect on the dynamic parameters of a simply supported bridge Laboratory experiments and numerical models = Evaluación del efecto de la temperatura en los parámetros dinámicos de un puente simplemente apoyado : experimentos de laboratorio y modelos numéricos

Abstract

We are interested in the effect of freezing and non-freezing temperature distributions on the dymamic parameters of a simply supported bridge. A laboratory scale model is placed on a climate chamber, where a uniform variation of temperature from 0 to 40°C is applied. Afterwards, a calibrated FEM model to simulate further freezing temperature scenarios. Above the freezing point, results show an increase of temperature has a direct correlation on the decrease of fundamental frequency, with amaximum variation of 0.92%. Laboratory non-uniform temperature distribution, across the deck, only presents a slight variation in fundamental frequency, not considering it a crucial parameter to be studied. Damage is also simulated on the finite elements model, where the variation of frequency caused by a severe damage scenario is within the same order of magnitude as the variation caused by a severe damage scenario is withun the same order of magnitude as the variation caused by uniform non-freezing temperature distribution. Furthermore, freezing temeprature scenarios, generated on an enhanced finite elements model show a correlation between bending vibrational modes and soil stiffness variation due to temperature. Under freezing. Under freezing temperature. Under freezing temperature scenarios, torsional vibrational modes are correlated with the variation of elasticity of the deck. Below the freezing point, frequency variation is up to twelve times higher tahn non-freezing results for simply supported configurations. Finally, a simplified normalization method for data under temperature varyng condition is proposed. For more complex structures, the evaluation of temperature effect should be addressed in order to avoid misdiagnosed bridge conditions through automated structural health monitoring systems (SHMS).