Design of Optimal Damper Values for a Stainless-Steel Footbridge Using Sensitivity Analysis

The subject of the article is a description of the procedure for determining the optimal values of the Tuned Mass Damper (TMD). Apply a TMD is one of the options to ensure that the serviceability criteria of a light bridge structure are met. The relations derived for the two-degree system are used to determine the stiffness, damping and mass of the shock absorber. This procedure cannot be used for moving loads. The damper reduces the response to only one eigen shape, it is generally ineffective for others. Therefore, the effort is to minimize the weight of the additional mass. The parameters depend on the selected optimized function, whether the goal is to minimize displacements or acceleration. Another aspect discussed in the article is the change of parameters due to the presence of pedestrians on the footbridge. The calculation model of the footbridge was made in ANSYS software technology. Sensitivity analysis was performed and managed by the OptiSlang module. This module controls the generation of inputs for a geometrically nonlinear computational model and is used to evaluate the sensitivity and robustness of the results. The article is limited to the solution of the dynamic response of moving persons.