Viscous Damper Regulating Defined
The development of the so called clever fluids and viscous dampers founded upon them has enabled way more efficient and convenient vibration attenuation choices than previously. This sort of semi-active actuators are already used in quite a few industries: autos, washing machines, bridges, building structures to name a few. This is on account of the small size and especially to the fast regulation capability they present: they may be regulated in accordance with the exact specifications of your shaking system.
This short article presents the core theoretical resolution behind my viscous damper and a few concerns with regard to the study of shake. There are additional scenarios to control the attenuator, but I have identified this one quick and helpful enough. The solution is not my design and it is valid for virtually any viscous damper. I bow to Jeong-Hoi Koo, whose “Groundhook” algorithm or “velocity-based on-off groundhook control” (On-Off VBG) provided in his dissertation I utilized.
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.
Importance 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.