Investigation of dynamic behavior and seismic performance of cam-type response-amplification friction damper

The inerter-based response amplification device for dampers has been proposed to enhance seismic resilience, yet its real-world dynamic behavior lacks experimental validation. This study investigates a Cam-Type Response-Amplification Friction Damper (CRAFD) through shaking table test of full-scale steel frame subjected to nine seismic records (including near/far-field events). Key findings reveal that the CRAFD achieves: (1) Target amplification of friction forces (8 kN vs lateral FD’s 1.2 kN) and inertial mass, inducing significant negative stiffness in the primary structure; (2) The natural frequency decreased by a maximum of 34% (from 2.9 Hz to 1.91 Hz) under 0.4 g inputs, and the equivalent damping ratio was significantly improved compared to traditional FD; (3) Higher displacement mitigation and acceleration reduction by maintaining sliding status, which elevates energy dissipation ratio and prevents structural damage; (4) CRAFD suppresses out-of-plane deformation in V-shape linkages. These results validate CRAFD’s efficacy in seismic response control for engineering applications.