Amplified viscously damped coupling beam (AVDCB): A high-efficiency seismic damping solution for coupled wall structures

This paper introduces a fully open-space damping amplification scheme, the Amplified Viscously Damped Coupling Beam (AVDCB). The AVDCB integrates a lever-arm amplifier into a standard viscous damped coupling beam (VDCB), utilizing a leverage ratio as a controllable amplification factor to enhance the damper performance during earthquakes. Dynamic cyclic loading tests are performed on both AVDCB and VDCB specimens to assess their hysteretic behavior. Numerical models, validated against experimental data, are developed, and a parametric study examines the impact of amplification factors and damper parameters on the AVDCB’s performance enhancement relative to the VDCB. Seismic response and damage mitigation of AVDCB are further assessed through time-history analysis of a 20-story building. The results show that the AVDCB significantly increases viscous damper deformation and velocity, leading to a marked increase in shear force and energy dissipation compared to the VDCB with identical dampers. The amplification effect of AVDCB is most pronounced when higher amplifier’s amplification factors and damper’s damping exponents are employed, although excessively high damping exponents may lead to excessive outputs under intense shaking. The equivalent relationship between the AVDCB and VDCB is established through an energy dissipation equilibrium, revealing that the AVDCB achieves seismic mitigation more efficiently than VDCB by using smaller damper sizes. A case study shows that AVDCB, compared to conventional RC coupling beams, reduces peak roof acceleration by over 50 %, and both base shear and structural deformation by more than 35 % under frequent-level earthquakes. Under rare-level earthquakes, base shear and structural deformation are reduced by over 24 %, providing significant damage protection. This highlights that the proposed AVDCB offers a highly efficient and space-friendly solution for improving seismic resilience of coupled wall structures.