Vol.:(0123456789) 1 3 International Journal of Steel Structures https://doi.org/10.1007/s13296-019-00267-7 Natural Rubber Bearing Incorporated with Steel Ring Damper (NRB‑SRD) Javad Sheikhi 1  · Mojtaba Fathi 1 Received: 22 January 2019 / Accepted: 1 August 2019 © Korean Society of Steel Construction 2019 Abstract The present paper is aimed to investigate the behavior of Natural Rubber Bearing incorporated with steel ring damper (NRB- SRD). These types of dampers are integrated of several steel rings which are considered with two configurations namely, continual steel ring damper and separate steel ring damper and are inserted between top and bottom plates. The performance characteristics of the system such as effective horizontal stiffness, energy dissipation, equivalent viscous damping and residual deformation are calculated and then compared with the results of high damping rubber bearings and also shape memory alloy (SMA)-lead core rubber bearing (SMA-LRB). The results show that the energy dissipation in steel rings are mainly based on plastic deformation due to flexural behavior of the rings. NRB-SRD shows better performance in energy dissipation compar- ing to SMA-LRB and HDRB. These additional dampers show higher stability and energy dissipation in low shear strains due to developing of link between structure and substructure having desirable initial stiffness under weak earthquakes and wind loads and also in higher shear strains due to creation of higher energy dissipation, stability and secondary stiffening. Keywords Rubber bearing · Steel ring damper · Energy dissipation 1 Introduction Several types of control systems including active, semi- active and passive control systems have been developed to systematically control the structure under destructive effects of earthquakes (Di Sarno and Elnashai 2005). The passive control systems have been highly focused and various types have been invented and applied due to simple and economi- cal design without any necessity to external resources of energy and function merely with initiated vibration in struc- ture comparing to modern control systems. The passive con- trol systems are generally categorized in seismic isolation systems that restrain or significantly mitigate the applied seismic energy to the structure and energy dampers that dis- sipate the main applied energy to the structure. Limited shear strain capacity, irreversible residual deformation and instability due to high displacements are accounted as disadvantages of rubber bearings (Choi et al. 2005). The researches reveal that application of lead core (Robinson 1982; Skinner et al. 1993; Hwang and Chiou 1996), high damping rubber materials (Tsai et al. 2003; Dall’Asta and Ragni 2006; Mordini and Strauuss 2008) and shape memory alloy (SMA) wires (Dolce et al. 2000; Ozbulut and Hurlebaus 2010; Hedayati Dezfuli and Alam 2013, 2015), bars (Wilde et al. 2000) and SMA springs (Attanasi and Auricchio 2011) in rubber bearings can rela- tively overcome the limitations of rubber bearings. The application of hysteretic steel dampers in structures was firstly proposed by Kelly et al. (1972) and Skinner et al. (1974). The cyclic response of U-shaped steel dampers was studied under different strain velocities and temperatures and found that U-shaped steel dampers show stable hysteretic cyclic response even in high displacements in horizontal directions (Suzuki et al. 2005). The seismic behavior of base-isolated frames with U-shaped hysteretic energy-dissi- pating devices were experimentally studied (Oh et al. 2013). It found that the seismic behavior of base-isolated frames with U-shaped dampers is better than fixed-base structures. The behavior of dual-pipe dampers was studied and reported proper ductility, high energy absorption and cost efficiency of such dampers (Maleki and Mahjoubi 2013–2014). Com- prehensive experimental and numerical studies have been conducted on steel rings made of plates and application in Online ISSN 2093-6311 Print ISSN 1598-2351 * Mojtaba Fathi fathim@razi.ac.ir 1 Department of Civil Engineering, Engineering Faculty, Razi University, Kermanshah, Iran