Modeling and Control of Magnetorheological Dampers for Seismic Response Reduction
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Citations
Adaptive fuzzy control for nonlinear building-magnetorheological damper system
Semi-active fuzzy control of a wind-excited tall building using multi-objective genetic algorithm
Design and Modeling of a Magnetorheological Valve with Both Annular and Radial Flow Paths
Integrated vibration control and health monitoring of building structures using semi-active friction dampers: Part I—methodology
Optimal design of hysteretic dampers connecting adjacent structures using multi-objective genetic algorithm and stochastic linearization method
References
Method for Random Vibration of Hysteretic Systems
Active Structural Control: Theory and Practice
Phenomenological Model of a Magnetorheological Damper
Commercial magneto-rheological fluid devices
Elastic and inelastic stress analysis
Related Papers (5)
Semiactive Control Strategies for MR Dampers: Comparative Study
Large-scale MR fluid dampers: modeling and dynamic performance considerations
Frequently Asked Questions (19)
Q2. What have the authors stated for future works in "Modeling and control of magnetorheological dampers for seismic response reduction" ?
Efforts are currently underway to investigate this possibility.
Q3. What is the force-velocity relationship of the MR damper?
At 0 V the MR damper primarily exhibits the characteristics of a viscous device (i.e., the force-displacement relationship is approximately elliptical, and the force-velocity relationship is nearly linear).
Q4. How long can the damper be operated?
The peak power required is less than 10 watts, which could allow the damper to be operated continuously for more than an hour on a small camera battery.
Q5. What are the advantages of semi-active control devices?
Semi-active control devices potentially offer the reliability of passive devices, yet maintain the versatility and adaptability of fully active systems.
Q6. What is the description of MR dampers?
They offer highly reliable operation at a modest cost and can be viewed as fail-safe in that they become passive dampers should the control hardware malfunction.
Q7. How many buildings have been successfully constructed?
To date, active structural control has been successfully applied in over twenty commercial buildings and more than ten bridges (during erection) [20].
Q8. What is the displacement of the MR damper?
Because the MR damper is attached between the first floor and the ground, its displacement is equal to the displacement of the first floor of the structure relative to the ground, i.e., in Eqs. (1–4).
Q9. Why did the semi-active controller perform better than the passive-off and passive-on control?
Because the semi-active system has the ability to vary its properties to more effectively control the structure, the clipped optimal controller performed better than both the passive-off and passive-on control systems.
Q10. Why is the MR damper unable to be operated continuously for more than an hour?
This behavior is primarily due to the time the MR fluid in the damper takes to reach rheological equilibrium and the time lag associated with the dynamics of driving the electromagnet in the MR damper.
Q11. How long does the MR damper take to rise?
The rise time (defined as the time required to go from 10% to 90% of the final value) in the force generated by the MR damper during a constant velocity test when a step in the voltage is applied to the current driver is approximately 8 msec.
Q12. What is the way to induce the MR damper to produce the desired control force?
If the magnitude of the force produced by the damper is smaller than the magnitude of the desired optimal force and the two forces have the same sign, the voltage applied to the current driver is increased to the maximum level so as to increase the force produced by the damper to match the desired control force.
Q13. What are some of the common types of semi-active devices?
Various semi-active devices have been proposed which utilize forces generated by surface friction or viscous/viscoelastic-plastic fluids to dissipate vibratory energy in a structural system.
Q14. What is the performance of the semi-active control system?
The performance of the semi-active control system employing the MR damper was found to be modestly better in reducing peak displacements than that of the linear active controller, indicating that the semi-active control system is capable of not only approaching, but surpassing, the performance of linear active control system, while only requiring a small fraction of the power that is required by the active controller.
Q15. What is the way to control the MR damper?
When the MR damper is providing the desired optimal force (i.e., ), the voltage applied to the damper should remain at the present level.
Q16. What is the way to measure the displacement of a structure?
Because accelerometers can readily provide reliable and inexpensive measurement of accelerations at arbitrary points on the structure, development of control methods based on acceleration feedback is an ideal solution to this problem and will be presented subsequently.
Q17. What are the structural measurements used for calculating the desired control force?
The structural measurements used for calculating the desired control force include the absolute accelerations of the three floors of the structure, and the displacement of the MR damper (i.e., ).
Q18. What is the definition of a semi-active control device?
According to presently accepted definitions, a semi-active control device is one which cannot input energy into the system being controlled.
Q19. What is the equation of motion for a MR damper?
Assuming that the forces provided by the MR damper are adequate to keep the response of the primary structure from exiting the linear region, then the equations of motion can be written as(9)ż