Development and application of a deformation-amplified self-centering energy dissipation device

Suitable seismic response reduction devices can substantially improve the seismic performance of engineering structures. However, devices with wide applicability and multi-function are lacking. A novel deformation-amplified self-centering energy dissipation (DA-SCED) device suitable for reducing the seismic response of different engineering structures is proposed in this paper. Self-centering of the device is achieved by a pre-pressed combined steel disc spring. The elastic–plastic hysteretic deformation of the lead rod is used to dissipate the earthquake energy. The shear deformation of the lead rods is amplified because the arc lengths of the lead rod embedded points and the connecting rod hinged point are proportional to the distances of both to the disc center when the steel disc rotates; the former distance is designed to be larger than the latter. Pseudo-static tests were conducted under reciprocating tension and compression of a full-scale model to determine the mechanical properties and seismic energy dissipation capacity of the device. A numerical simulation was performed to analyze the factors influencing mechanical performance. In addition, a restoring force model of the device was established and verified, and the seismic energy dissipation capacity was studied using a prefabricated segment pier. The results indicate that the DA-SCED device has good self-centering and energy dissipation abilities. Its hysteresis curves show flag-shaped characteristics, and the maximum residual displacement after unloading is only 0.97 mm. The self-centering capacity can be improved by increasing the disc spring pre-pressure, and the energy dissipation capacity can be enhanced by increasing the deformation amplification ratio and the diameter and number of the lead rods. The proposed restoring force model can describe the mechanical properties of the device accurately. Furthermore, the DA-SCED devices used in the prefabricated segment pier have satisfactory energy dissipation and self-centering performance under seismic action. After installing the device at the bottom of the pier, the transverse and longitudinal opening deformations between the cushion cap and bottom segment are decreased by 41.52 % and 46.75 %, the displacements of the pier top are reduced by 16.34 % and 31.63 %, and the shear forces of the pier bottom are reduced by 12.26 % and 11.96 %, respectively. The device can reduce the seismic responses and the level of damage to the pier, and improve the self-centering ability and seismic performance of the structure.