yes i can reach the tower easily because it´s near the beach, this is a thesis in civil engneering, and one of the aims it´s to place a TLD ( Tunned liquid Damper), i must place in the top of the tower a TLD to solve the problem, but thank you for the idea.
thank you for your help, the antenna is from a danmark manufacturer, i´m sendind the caracterisctics for you, the problem is the forces/oscilation that induces in the tower.
The ideia do diminuish these effect is to place a tank of water in the top of the tower, a TLD ( Tunned liquid damper)...
Hello Baluncore the natural frequncy of the tower assembled is 1.54 Hz ( i have a computer model). Yes the idea that change the frequency placing a water tank in the top of te tower moust likely with the form of a donut, because in the top of the platform is the pedestal of the antenna, or place...
That is truth they didn´t place the antenna is the best place to reduce the displacements, but even if the had had that care there is allays uncertain because in the realitty the centre of gravity is hard to define, because there are variable you can´t control like the imperfectiond of the...
Thank you very much JBA for you ideas, they are very interesting, that will help me to understand better the problem.It took a bit to understand, because my english is nor very good.
Regarding the wind force, in the case of the drag force, that produces imbalanced force, can be calculated...
i didn´t measure the osillation (circular) but in the ground can be easily seen, the wind normally is from a constant direction, the antenna is located in shore next to the sea. In calm weather also oscillate.
Thank you for your help, it´s actually a observed precession on a already installed mettalic tower, but it´s also objet of a study for my thesis in civil engineering in order to understand why this precession ( oscillation occurs in the tower, when the radar antenna is in motion).
The tower...
1- the antenna + motor weights about 400 Kg (the helix weights about 170 Kg and has adiameter of 6.28 m, and the motor of the antenna weights 230Kgs), there is an excentricity between the centre of gravity of the antenna + motor and the centre of rotation of the anetnna which is 42 mm in the yy...