TRANSFER FUNCTION DEFORMATION MECHANISM DUE TO WIND FORCE EFFECT ON BUILDINGS DURING MICROTREMORS

Abstract

System identification using a transfer function obtained from the spectral ratio for buildings during microtremors and with soil-structure interaction has advantages and disadvantages. The advantages are that the vibration modes and dynamic characteristics of the buildings themselves can be obtained under small wind velocity conditions. A disadvantage is that the wind force deforms the spectral ratio. This paper describes a study of this phenomena. Three factors were studied: the existence of upper input forces, simultaneous upper and lower input situation, and relation (dependence or independence) between two input forces. Furthermore, it was explained mathematically that the relative magnitudes of base movements due to the upper and lower input forces control this phenomena.