Steel tubular friction damper and vibration reduction effects of double-layer reticulated shells

A steel tubular friction damper (STFD) is proposed for vibration reduction in large-span spatial structures. The effects of the amplitude of the applied displacement, the pre-tightening force of the high-strength bolts, and the material of the friction plates on the hysteretic behaviour of the STFD are analysed experimentally. The single-cycle energy consumption increases and the equivalent stiffness decreases with increasing displacement amplitude. In addition, the single-cycle energy consumption and equivalent stiffness of the SIM increase with increasing pre-tightening force. Both the single cycle energy consumption and the equivalent stiffness of the STFD with aluminium alloy or brass friction plates are larger than that of the STFD with steel friction plates. Then, a mechanical model of the STFD is established for further numerical analysis. Several structural members in a 40-m-span double-layer reticulated shell are replaced with STFDs to provide vibration reduction. Optimal arrangement of STFDs is studied based on additional modal damping ratio. The effects of the replacement rate, earthquake intensity and various ground motions on the vibration reduction effect are investigated via numerical analyses. The reduction ratio first increases and then decreases with increasing replacement rate, and the best performance is observed at a replacement rate of 10%. The vibration reduction effect of the STFDs is more obvious for strong ground motions than for weak ground motions. Under various ground motions, the vibration reduction effect of the STFDs is better for the two ordinary ground motions than for the four long-period ground motions selected herein. (C) 2020 Elsevier Ltd. All rights reserved.