Before moving to structural damping towers let’s first discuss the damping
What is Damping?
Damping is the restraint of vibratory motion by energy dissipation. If a child does not continue to move a swing the damping will suppress the motion. For starters, shock absorbers and carpet pads are the best examples of damping devices.
The mechanism may not vibrate so damply. Effective essential damping prevents vibration or is sufficient to allow the individual to return to his place of rest as soon as possible.
The automotive shock absorbers are an example of a critically damp system.
The machine is overdamped with further damping, which, as in specific door closers, is beneficial. The underdamped system vibrations slowly diminish to zero.
What are Damping Pads?
A damping pad used to increase the structural damping towers.
There are two components: the one between the anchor bolt and the chair plate is a damping or washing bag, while the other a large pad fits between the base plate and the concrete base leveller and the shim plate.
Damping pads are of different types have their own property damped. The damping pad usually consists of the top and bottom of an elastomer layer with the cork layer in the centre.
The pads for a new stack are cheap and better used. For an existing operational stack, the installation costs for these pads may be high. Such pads have disadvantages:
(1) they may not tolerate temperatures above 200 ° F, and
(2) they will worsen if exposed to hydrocarbons, and
(3) they may have to be maintained and tested for pads.
The pads for damping, used for concrete stacks placed on the foundation. The interaction effects of the frame for stacks in buildings included after ASME STS-1. In fact, the building and storage of the frame are involved. The steel structure and the stack, designed together when stacks mounted on steel structures such as exhaust systems. This analysis analyzes the structural rigidity.
Also, read about Eurocodes
structural damping towers
What are the different types of Damping?
Friction Damping is mostly a function of the electrostatic attraction forces between sliding surfaces, also known as dry or coulombs in this sense, converting the mechanical energy of movements or kinetic energy into heat.
The motion of a vibrating body is set by the moving gas or fluid. The damping power of the fluid, in this case, is slightly less than that of the body’s square of the speed known as the velocity-squared damping.
Viscous damping, caused by energy losses, such as in automobile shock absorbers, made by liquid grafting between moving parts or by fluid forced by the piston opening. The force of viscous damping correlates directly to the relative speed of the damping mechanism between the two ends.
Besides this external damping, the moving mechanism itself has an energy loss known as hysteresis or structural damping. For hysteresis, the energies involved in a repetitive inner deformation and restoration of the original form dispersed into solids of the crystal grid in random vibrations and the molecule’s kinetic energy changes in the fluid.
In the case of alternating current, like in a radio or TV recipient, electric resonance circuits influenced by electrical damping. The signal transmitted by the receiver provides energy for resonance damping synchronously.
In the case of damping radiation, vibrational energy such as electric charges converted in radiation damping into electromagnetic power and released by radio waves or infrared or visible illumination.
For magnet damping, movement energy becomes heat by the electrical eddy currents moving through the magnet poles caused in both a spindle and an aluminium plate (contained to the oscillating object).
Viscous and structural damping is used in structural damping towers
What is the Difference between Structural and Material Damping?
Damping substantially reduces oscillations (or oscillations ‘ magnitude) by energy loss. There is a simple damping property for every device.
Again, it divides into Structural as well as Material. Basically, all Materials will possess some damping nature, and it can increase or decrease on how well we Structure (design) the Material.
For example, Aluminium damping ratio is~0,0004 as a material but it can also increase on the base of the structure (i.e. geometry changes, stiffness, support configuration and elasticity module)
Also, In areas where two different materials used to produce a design, the materials damping will be more specific. It is relevant that there is an analysis of the loss of hysteresis here.
But typically, the structural damping and the damping of materials together shape the damping curve of this particular design when a design formed.
Structural Damping Towers and Wind Turbines
A standard structural damper for wind turbines consists of an auxiliary mass connected to the main structure via springs and dash points. The natural frequency of the tuned mass damper continuous spring and damping of the dash point.
The tuned mass damper parameter allows the auxiliary mass to oscillate with structural motion in phase shifts. Typically, an auxiliary mass hangs under the nacelle of a wind turbine with dampers or friction plaques.
Wind Turbine Structural Damping Tower Control
Wind turbines are subject to complex dynamic conditions of the load because they are excited spontaneously. The construction of large wind towers and sub-structures on the coast, as well as offshore wind farms, is increasingly challenging.
Different structural damping strategies, like tuned mass dampers, introduced in recent years to maintain the structural integrity of multi-megawatt wind turbines.
In order to reduce the excitement from side to side and to control the blade pitch, other techniques depending on the control measurements. They are available as the torque control of the generator reduces the forward movements.
All of these strategies, designed to limit fatigue and bend loads and interact dynamically with rotor harmonics without increasing materials (i.e. costs).
It is clear that the achievable load reduction can be up to 20% insignificant design cases. The mass of the structural damping tower can decrease by up to 10%.
