MODAL ANALYSIS OF INTAKE TOWERS. THE INFLUENCE OF COMPUTATIONS SIMPLIFICATIONS.

Many simplifications are often made, in calculating of eigenmodes and eigenvalues of stuctures. The mass of a structure is distributed throughout the structure. However, in most cases, mass can be considered concentrated in the nodes of the structure. The procedure consists in concentrating the mass of the elements at each end thereof, followed by the summation of the mass of the elements that compete in the corresponding nodes. Generally, rotating mass components have a minor influence on the dynamic response of structures and are neglected. The removal of degrees of freedom from the stiffness matrix is achieved by static condensation. The number of points in which the mass of the structure is concentrated may be larger or smaller, resulting in more complex structures (large number for degrees of freedom) or simpler. Consideration of soil interaction through different calculation models also influences modal parameters. The article analyzes the influence of these simplifications, exemplifying the calculation of the modal parameters for the intake tower from the accumulation of Sarca, Iasi County, Romania [ABSTRACT FROM AUTHOR]