Structural Engineering and Mechanics

Volume 81, Number 3, 2022, pages 317-333

DOI: 10.12989/sem.2022.81.3.317

Cyclic testing of a new visco-plastic damper subjected to harmonic and quasi-static loading

Ahmad Modhej and Seyed Mehdi Zahrai

Abstract

Visco-Plastic Damper (VPD) as a passive energy dissipation device with dual behavior has been recently numerically studied. It consists of two bent steel plates and segments with a viscoelastic solid material in between, combining and improving characteristics of both displacement-dependent and velocity-dependent devices. In order to trust the performance of VPD, for the 1st time this paper experimentally investigates prototype damper behavior under a wide range of frequency and amplitude of dynamic loading. A high-axial damping rubber is innovatively proposed as the viscoelastic layer designed to withstand large axial strains and dissipate energy accordingly. Test results confirmed all assumptions about VPD. The behavior of VPD subjected to low levels of excitation is elastic while with increasing levels of excitation, a significant source of energy dissipation is provided through the yielding of the steel elements in addition to the viscoelastic energy dissipation. The results showed energy dissipation of 99.35 kN.m under a dynamic displacement with 14.095 mm amplitude and 0.333 Hz frequency. Lateral displacement at the middle of the device was created with an amplification factor obtained ranging from 2.108 to 3.242 in the rubber block. Therefore, the energy dissipation of viscoelastic material of VPD was calculated 18.6 times that of the ordinary viscoelastic damper.

Key Words

equivalent viscous damping ratio; finite element analysis; metallic yielding devices; passive control devices; viscoelastic damper

Address

Ahmad Modhej: Department of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran Seyed Mehdi Zahrai: School of Civil Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Iran; Civil Engineering Department, University of Ottawa, Canada