A HIGHLY-TUNABLE NOVEL ROCKING TUBE DAMPER (RTD)

Self-centering rocking systems with passive energy dissipation devices have been studied extensively in the literature because of their low-damage seismic behaviour and resilience.The rocking mechanism is typically a feature of the structural system, and some form of supplemental energy dissipation system is often added to the structure to absorb energy and limit displacement response.This paper proposes a new Rocking Tube Damper (RTD) which incorporates a gap opening rocking mechanism into a scalable and non-invasive supplemental damping device.The selfcentering rocker is preloaded with a stack of partially compressed conical spring washers.These conical spring washers provide elastic deformation capacity, and together with the applied preload produce a largely bi-linear elastic response that creates an initial resistance to motion and controlled inelastic behaviour.The RTD has been previously modeled to establish its force-displacement response, showing an ideal bilinear elastic hysteresis with zero residual deformation.A prototype of the selfcentering rocker has been fabricated and experimentally tested under cyclic loading.The experimental response matches the broad behaviour expected from the numerical model.However, initial experimental test results exhibited some inherent energy dissipation from friction than was not included within the mathematical model.Suggestions are made for ongoing work to further investigate the full range of response behaviors of the RTD concept.