Estudio experimental de las frecuencias fundamentales de modelos estructurales ante sismos escalados y artificiales.

Abstract

The instrumentation of buildings allows us to evaluate and analyze the design of an existing building, and identify possible damage after the occurrence of a moderate to severe seismic event, considering the fundamental frequency as an essential parameter in the Dynamics of Structures. The purpose of this study is to analyze the fundamental frequencies of six structural models, and to compare the results obtained with the Modal Spectral and Step by step descriptive methods of analysis over time. The experimental analysis was carried out on the Quanser XY Shake Table III vibration table using three cortical and three subduction seismic recordings, in addition to four appropriately generated artificial accelerograms. The experimental phase consisted of the construction and testing of the models, finding the recorded accelerations of the earthquakes and selected accelerograms scaled to a displacement of 2.5 cm. Finally, the dynamic responses obtained experimentally were taken from the time domain to the frequency domain through the Fast Fourier Transform, for which a subroutine was developed in MATLAB that included the Butterworth filter and smoothing using the Konno & Ohmachi function, which directly processes the accelerations delivered by the accelerometer.