Cyclic Testing of Multilevel Pipe in Pipe Damper

In this paper, the experimental results of the new multi-stage damper and practical manufacturing details are presented. The proposed damper consists of a combination of nested pipes that could change dynamic behavior parameters like strength, stiffness and damping ratio. Cyclic quasi-static tests were performed on two samples. Results show suitable energy absorption, ductility and stable hysteresis curves in the specimens. Also, multi-level performance can dissipate energy in different input energy levels. Moreover, achieving high equivalent viscous damping ratios up to 38% is noticeable. The proposed device is light-weight and easily fabricated, demonstrating suitable cyclic performance to reduce the seismic vibrations.