Modeling thermal effects on bridge dynamic responses

International audienceThe paper seeks to analyze the influence of temperature on the dynamic behavior of bridges. The objective is to propose a model that can be used to analyze the validity of damage detection algorithms that seek to separate variations in the modal properties due to damage or temperature. One first shows how temperature changes generate thermal stresses which, depending on the boundary conditions, can generate pre-stress levels that are sufficient to induce frequency shifts in the response. A procedure to compute these effects and generate low dimension reduced models with temperature appearing explicitly is proposed. This procedure is then illustrated for a simplified bridge and a realistic one for which test results are available