The improvement of the so called smart fluids and viscous dampers founded on them has enabled considerably more efficient and convenient vibration attenuation possibilities than ever before. This kind of semi-active dampers are already used in many industrial sectors: cars and trucks, washing machines, bridges, constructing structures to name a few. This is as a result of the small size and particularly to the quick regulation potential they give: they usually are controlled in accordance with the precise demands of your shaking system.
This short article provides the central theoretical resolution associated with my viscous damper and some considerations about the examination of the vibrations. There are alternative scenarios to regulate the damper, but I have found this one straightforward and handy enough. The method is not my creation and it goes for any viscous damper. I give credit to Jeong-Hoi Koo, whose "Groundhook" algorithm or "velocity-based on-off groundhook control" (On-Off VBG) shown in his dissertation I applied.
Groundhook Law on Two-Degree-of-Freedom System
The context where the control rule is provided is a two-degree-of-freedom mass-spring-damper system. The basic principle of a groundhook law is that the mass whose vibration is damped, is connected to the floor via a damping element. The semi-active part is the controlled, viscous damper which is positioned in between the shaking masses. The control law is uncomplicated: when the higher vibrating weight is moving up and the lower weight downwards, tension is employed to the viscous damper. This induces a pulling force to the structure mass in direction of the stability situation of the system.
Groundhook Law Made Easy on Single-Degree-of-Freedom System
Nevertheless, as a direct consequence of a presupposition or an approximation, this law is often made simple. Should th velocity of the lower mass is estimated to be really small and at the same phase with the vibrating mass all the time, the system may be modelled with a single-degree-of-freedom vibration system. If your higher shaking mass is going right up and the lower weight stays put, strain is applied to the viscous damper. That triggers just as before a pulling force to the structure weight toward the stability position of the system.
Relevance of Understanding Your Shake
For you to acquire the most out of the damping potential of a viscous damper, you will need to extensively understand your vibrating system. This means that, you will need to measure the shake of the target correctly to find out the distressing frequencies, their amplitudes and the time instant when the frequencies occur (for instance three seconds from startup).
Only after measuring these, you can come up with how a semi-active viscous damper would solve the situation. Or perhaps you will determine that a classic passive damper is a more feasible solution. Even so, when integrating smart control algorithms on your solution, you should always review the shake system thoroughly.
This short article provides the central theoretical resolution associated with my viscous damper and some considerations about the examination of the vibrations. There are alternative scenarios to regulate the damper, but I have found this one straightforward and handy enough. The method is not my creation and it goes for any viscous damper. I give credit to Jeong-Hoi Koo, whose "Groundhook" algorithm or "velocity-based on-off groundhook control" (On-Off VBG) shown in his dissertation I applied.
Groundhook Law on Two-Degree-of-Freedom System
The context where the control rule is provided is a two-degree-of-freedom mass-spring-damper system. The basic principle of a groundhook law is that the mass whose vibration is damped, is connected to the floor via a damping element. The semi-active part is the controlled, viscous damper which is positioned in between the shaking masses. The control law is uncomplicated: when the higher vibrating weight is moving up and the lower weight downwards, tension is employed to the viscous damper. This induces a pulling force to the structure mass in direction of the stability situation of the system.
Groundhook Law Made Easy on Single-Degree-of-Freedom System
Nevertheless, as a direct consequence of a presupposition or an approximation, this law is often made simple. Should th velocity of the lower mass is estimated to be really small and at the same phase with the vibrating mass all the time, the system may be modelled with a single-degree-of-freedom vibration system. If your higher shaking mass is going right up and the lower weight stays put, strain is applied to the viscous damper. That triggers just as before a pulling force to the structure weight toward the stability position of the system.
Relevance of Understanding Your Shake
For you to acquire the most out of the damping potential of a viscous damper, you will need to extensively understand your vibrating system. This means that, you will need to measure the shake of the target correctly to find out the distressing frequencies, their amplitudes and the time instant when the frequencies occur (for instance three seconds from startup).
Only after measuring these, you can come up with how a semi-active viscous damper would solve the situation. Or perhaps you will determine that a classic passive damper is a more feasible solution. Even so, when integrating smart control algorithms on your solution, you should always review the shake system thoroughly.
About the Author:
If you'd want to get more info about viscous dampers, look into Magnetorheological Damper Laboratory, which is devoted to explain the details of controlling a viscous damper.
