Experimental Investigation and Computational Modeling of Seismic Response of a 1:4 Scale Model Steel Structure with a Load Balancing Supplemental Damping System

Keywords: Steel moment frames. Seismic response. Elastomeric spring dampers. Damper configuration. Shake table tests. Structural response. Fuse bars. Tendon systems. Energy dissipation devices. Damping systems.
Abstract: An experimental study to investigate the seismic behavior of steel structures under the simulated ground motions is described. It is argued that damper distribution should be based on 1) either the interstory deformation or story shears, and 2) the overturning moments generated by the lateral inertia loads. The former method was implemented in a non-ductile reinforced concrete frame (Pekcan, et al, 1995), while for the latter method an innovate prestressed load-balancing tendon system was introduced in this report. Approximate alternatives were experimentally explored on a model steel structure. This load-balancing supplemental system consists of prestressed-draped tendons in the shape of the overturning moment diagram. The tendons are connected in series with the nonlinear dampers and sacrificial fuse-bars. It is concluded that the load-balancing tendon-fuse plus damper system is an appropriate cost-effective method of mitigating the earthquake induced demands on a steel frame. By careful detailing, it is possible to ensure that under design earthquake loads the structure remains elastic, while under maximum credible motions fracture of the steel frame welded connections can be avoided.