Semi-active predictive control method for bridge pier-magnetorheological bearing vibration isolation system

Abstract

The invention discloses a bridge pier-magnetorheological bearer vibration isolation system semi-active prediction control method comprising the following steps: building a vibration equation of the bridge pier-bearer system under an impact load effect; considering retardation time existing in the system and writing the vibration equation into a state space according to girder displacement, speed and acceleration information collected by sensors, and building a vibration isolation system state equation under the impact load effect; discretizing the bridge pier-bearer vibration isolation system state equation under the impact load effect; building a bridge pier-bearer vibration isolation system semi-active prediction model; selecting performance indexes of a bridge pier-magnetorheological bearer vibration isolation prediction control system; solving the bridge vibration isolation system optimal control acting force. The method imports a semi-active prediction control algorithm into the bridge pier-magnetorheological bearer vibration isolation system, thus solving the problems that a magnetorheological bearer is poor in control effect in the bridge vibration isolation system, and reducing the influences on the control performance by the unavoidable existing retardation time in the system.

Description

technical field The invention relates to the field of structural vibration control, in particular to a semi-active predictive control method for a bridge pier-magnetorheological support vibration isolation system. Background technique In order to improve the vibration isolation and buffering capacity of bridge piers, supports are usually installed at the junction of bridge piers and main girders to reduce the damage to bridges caused by earthquakes by prolonging the structural vibration period; although traditional passive supports have good vibration reduction under certain excitation conditions ability, but under the impact of large loads, it cannot intelligently adjust its own stiffness and increase the vertical strength to resist impact and large deformation, and reducing the transmission force and support displacement itself is a pair of contradictions in the anti-shock energy absorption of bridge piers. The lack of good shock resistance and vibration isolation compatib...

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Problems solved by technology

In order to improve the vibration isolation and buffering capacity of bridge piers, supports are usually installed at the junction of bridge piers and main girders to reduce the damage to bridges caused by earthquakes by prolonging the structural vibration period; although traditional passive supports have good vibration reduction under certain excitation conditions ability, but under the impact of large loads, it cannot intelligently adjust its own stiffness and increase the vertical strength to resist impact and large deformation, and reducing the transmission force and support displacement itself is a pair of contradictions in the anti-shock energy absorption of bridge piers. The lack of good shock resistance and vibration isolation compatibility has become the weakest link in the bridge structural safety system, often leading to earthquake damage such as pier girder displacement and falling beams, which has brought great impact to the safety of the bridge structure. Hidden danger

With the development of smart materials, the magnetorheological bearing (MRB) has excellent mechanical adjustability under the action of magnetic field, and its shear modulus and damping loss factor have excellent mechanical adjustability under the action of large tension, compression or shear It still has a good deformation and energy dissipation capacity under the current international research. When the bearing is placed on the bridge system to face the impact of large loads such as earthquakes and impacts, it requires a certain amount of data acquisition, control law calculation, and control. time, which will inevitably lead to a lag in the control time, which has a great impact on the stability and performance of the control system, and the current research on semi-active control of structural vibration mainly focuses on the classical feedback control algorithm based on the global optimum, but the structural vibration of bridges must be Taking into account uncertain disturbance factors such as earthquakes and the uncertainty of its own parameters, this brings certain difficulties to the structural vibration control modeling based on the global optimum, and may cause large model deviations due to changes in stiffness and other changes that affect the overall seismic resistance of the structure sex

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