A new type of damper with friction-variable characteristics

Abstract

Professor T. T. Soong is one of the early pioneers in fi eld of earthquake response control of structures. A new type of smart damper, which is based on an Energy Dissipating Restraint (EDR), is presented in this paper. The EDR by Nims and Kelly, which has a triangle hysteretic loop, behaves like an active variable stiffness system (AVS) and possesses the basic characteristics of a linear viscous damper but has diffi culty in capturing the output and large stroke simultaneously needed for practical applicataions in engineering structures. In order to overcome this limitation, the friction surface in the original Sumitomo EDR is divided into two parts with low and high friction coeffi cients in this paper. The results of fi nite element analysis studies show that the new type of smart friction damper enables large friction force in proportion to relative displacement between two ends of the damper and has a large allowable displacement to fi t the demands of engineering applications. However, unlike the EDR by Nims and Kelly, this type of friction variable damper cannot self re-center. However, the lateral stiffness can be used to restore the structure. The nonlinear time history analysis of earthquake response for a structure equipped with the proposed friction variable dampers was carried out using the IDARC computer program. The results indicate that the proposed damper can successfully reduce the earthquake response of a structure.

A lattice‐shaped friction device and its performance in weak‐story prevention

“…The PEDD with a relatively low post‐yielding stiffness has no capacity to transmit the earthquake loads and energy to neighboring stories after the dampers yield, and the floor exposed to the most input energy becomes relatively weak. Previous investigations validated that the PEDD with considerable post‐sliding stiffness can provide an effective and feasible way to postpone the collapse of structures under catastrophic earthquakes …”

“…Previous investigations validated that the PEDD with considerable post-sliding stiffness can provide an effective and feasible way to postpone the collapse of structures under catastrophic earthquakes. [25][26][27] This paper presents a lattice-shaped friction unit (LSFU) contained horizontal steel strips, vertical steel strips, and diagonal steel strips and investigates the seismic performance of the proposed device. The basic construction of LSFU and the principle of the force exerted by the device itself are described first.…”

Mechanical Performance and Design Method of Improved Lead Shear Damper with Long Stroke

“…It required small shunt voltages, provided large stroke, and reduced the vibration of larger mechanical structures; the theoretical results were also presented [27]. In order to meet the needs of large stroke and large output of high-rise buildings, a new type of intelligent friction damper was proposed based on constrained energy dissipation system by Zhou and Peng [28]. Through the finite element analysis of damper and the nonlinear time history analysis of a structure equipped with dampers, it was proved that the new type of intelligent friction damper had larger friction force and larger allowable displacement, meeting the requirements of engineering applications.…”

Development and Analysis of the Control Effect of a Reid Damper with Self‐Centering Characteristics

“…e restoring force device uses the same parts as those in other self-centering dampers. e main methods of achieving variable friction include piezoelectricity [26], variable contact surface friction coe cient [27], and variable friction contact surface [28]. Nims et al developed an energy dissipating restraint (EDR), whose damping force is a combination of spring elasticity and friction, and the friction is proportional to the displacement [29,30].…”