Structural Control by Innovative Oil Damper with Automatic On/Off Valve Operation

Abstract

This paper discusses an ingenious passive oil damper for structural control that maximizes or minimizes the damping coefficient by regulating the opening of a built-in flow control valve. The on/off algorithm was originally developed for a semi-active oil damper using electrically controlled solenoid valves, and its control effectiveness was confirmed through vibration tests and observation records in actual high-rise buildings. The remarkable feature of the device proposed here is that all valve control is implemented autonomously using the pressure balance between two hydraulic chambers without external power, so it operates like a semi-active damper with no external energy or controller, and absorbs much more vibration energy than conventional dampers. Dynamic loading tests on a full-scale device (maximum force: 2.1 MN) under both sinusoidal and nonstationary waves confirmed that the device has the excellent energy absorption capacity anticipated and that the damper’s dynamics are well simulated by a simple analytical model. The damper is widely applicable and already has been or is being implemented in over 15 high-rise buildings in Japan.