Semiactive Viscous Tensile Bracing System

Abstract

Structural control using energy dissipater devices is emerging as a heavily researched strategy in earthquake engineering. Among several control systems, semiactive control is usually possible and efficient. In this research, a semiactive energy dissipating bracing system based on a viscous damper is proposed. In the conventional bracing systems, it is assumed that the braces can buckle under compression. Therefore, a semiactive on-off brace strategy is implemented to improve the conventional brace performance. Further, an energy absorbing mechanism is implemented. In the proposed system, the buckling of the member is prevented by implementing a one-way valve device. The permanent story drifts at the end of excitations are negligible. In this mechanism, any actuator and/or large power supply are not needed, instead, just battery-size power supplies to switch the one-way valve mechanical system on or off. The developed mechanism is composed of a viscous damper, a length correction control system, and a normal wind bracing on each floor. Despite the fact that this system does not get control command from the outside, it is called a semiactive control system. The hysteresis loop of the braces is almost similar to ductile tensile steel members. Therefore, the system is full capacity design. Nonlinear dynamic analysis of the system has been carried out and structural behavior has been investigated. In addition, damage indices are determined in order to compare the viscous tensile bracing system with the conventional bracing systems.