A numerical study on optimum shape of steel slit dampers

Steel slit dampers are among the passive energy dissipating devices that have been proposed to improve seismic performance of steel structures. Several experimental and numerical studies have also been carried out to investigate capacity of the dampers in energy dissipation. In this article, a numerical model is developed to obtain optimum boundary shape of the dampers. To achieve this, isogeometric analysis method is utilized as a powerful tool in precise modeling of complex geometries for the purpose of non-linear analysis of the dampers. A conventional steel slit damper shape is modeled by non-uniform rational B-splines, and then, the shape is optimized with the aim of maximizing the structural energy dissipation under a volume constraint. To verify the model, measurements of an experimental test in literature are compared with the model results. A mathematical-based approach is employed for the optimization process and analytical shape sensitivity analysis is performed. As a result of optimization process, a new steel slit damper is suggested and its performance is evaluated via comparing with other shapes suggested in the literature.