Seismic Performance Analysis and Design Method for the SMA-Friction Damper in Cable Dome Structure

Aimed at the seismic control of long-span spatial structures under earthquakes，a shape memory alloy (SMA)-friction damper suitable for long-span spatial structures is adopted，which combines the hyperelastic characteristics of SMA materials and high-energy-dissipation characteristics of the friction damper. The preferential arrangement of the damper is obtained via calculating the additional modal damping ratio，considering the cable dome structure of Tianjin University of Technology Gymnasium as the research object. Based on the multiscale finite element model，the seismic control performance of the cable dome structure under different earthquakes and the mechanical performance of the SMA-friction damper are analyzed. The results show that for the cable dome structure，the compression bars of its inner ring should be preferentially replaced. As the earthquake intensity increases from 0.07g to 0.40g，the sliding displacement of the damper increases，and the vibration reduction effect is enhanced. The average vibration reduction ratios of vertical peak acceleration of the mid-span node increase from 11.97% to 30.35%，the average vibration reduction ratios of vertical peak displacement of the mid-span node increase from 27.46% to 37.10%，and the average vibration reduction ratios of the peak compression bar stress increase from 8.29% to 11.55%. The first-order natural vibration frequency of the cable dome structure is low，close to the Fourier amplitude concentration region of long-period ground motions. A greater dynamic response will occur under long-period ground motions，resulting in a larger sliding displacement of the damper and a better energy dissipation capacity. The average vibration reduction ratios of vertical peak acceleration and peak compression bar stress can reach 36.85% and 15.13%，respectively，superior to those under ordinary ground motions. Finally，a parametric analysis is performed on the mechanical parameters affecting the hysteretic performance of the damper，including the pretension of high-strength bolts and the number of alloy wires. The mechanical parameter design method of the damper is obtained combined with the force of the damper in the structure，which can be used as a reference for practical design. © 2023 Tianjin University. All rights reserved.