Experimental Study On Flutter Suppression Of Long-span Suspension Bridges Based On Active Control Wing Panel

Using traditional fixed aerodynamic countermeasures to boost the aerodynamic performances has many limitations on long span suspension bridge,while the active aerodynamic measures will be able to solve the difficulties in the application of large span bridge flutter suppression.This provides new train of thought for bridge wind resistance design——The research on active flow control method.this paper studies the active control surface flutter control law by wind tunnel test.According to the test demand,we design and produce a set of experimental devices that suitable for two different modes--Combined control surface and separated control surface.In this control system,the position of the control surfaces fitted to the bridge section's leading and trailing edges are adjustable.In addition,motion phase angle and amplitude of the active control surfaces are also adjustable.They are responsive to the bridge section's heave and pitch motions.based on the section of the plate and box girder models,flutter suppression experiment was carried out.The effectiveness of the system in flutter active control is verified,and the optimal control law of the two aerodynamic measures is obtained.In this thesis,we discuss and verify whether the aerodynamic force of active control system can be linear,explore and establish new applicable active control model of nonlinear time-varying control system model according to the existing bridge flutter model of self-excited aerodynamic theory.in this paper,the main work and contributions are as follows:1)Designed and produced plate bridge section model with four servo motors as actuator drive.Set up the whole active control test system.transfer function of the actuator is established by controlling the surface drive motor to realize control surface corner instruction.2)find the optimal control law of active vibration suppression system(tablet and box girder model)Based on wind tunnel test.The control law is consistent with numerical simulation results.When the phase of windward side surface motion is 110 degrees lag the section's pitch motion,we will achieve the optimal vibration suppression effect.This method can boost the flutter critical wind speed up to at least 70 percent.3)A new control system model is proposed and discussed in this paper.