Re-centering Devices
Suhasini N. Madhekar, Vasant Annasaheb Matsagar · 2022
Re-centering ability of a response control device is its capability to return to its original (neutral) position/configuration after the occurrence of a dynamic excitation event, such as earthquake and wind. The absence of re-centering capacity in the structural response devices could lead to significant permanent residual deformations. This could lead to (i) significant damage to the structure or the control device and (ii) loss of stability of the structure, especially during the occurrence of the subsequent dynamic excitation. Therefore, it is very important for response control devices to possess re-centering capability. For structures and response control devices that do not possess adequate re-centering capacity, independent re-centering devices may be used to enhance their performance. For instance, response control devices, such as pure friction isolators, may be used together with re-centering devices. This chapter presents the details of various re-centering devices, such as the pressurized fluid damper, preloaded spring friction damper, self-centering seismic-resistant system, and shape memory alloy damper. The operational principles, the applicability, and the practical benefits of using the re-centering devices in structures under dynamic excitations are elaborated. Moreover, the re-centering devices, in addition to their re-centering capability, may also offer the benefit of dissipating the energy induced due to dynamic excitations.