The diaphragmatic effect of concentrated masses on the dynamic behaviour of a tapered thin-walled tower

The present paper deals with the non-linear dynamic analysis of a thin-walled tower with varying cross-section and concentrated masses. It, especially, deals with the effect of the rotary inertia and the diaphragmatic operation of those masses, which have been neglected up to now. Using Galerkin's method, we can find the spectrum of the eingenfrequencies and, also, the shape functions. Finally, we can solve the equations of the problem of the forced vibrations, by using Carson-Laplace's transformation. Applying this method on a tall mast with 4 concentrated masses, we can examine the effect of the rotary inertia of the above masses, because of seismic loads and, also, harmonic loads, caused by wind forces.