Dynamic response of a two-story steel structure subjected to earthquake excitation by using deterministic and nondeterministic approaches

Abstract

An earthquake is a random phenomenon in its intensity and frequency content. Since the earthquake is a signal that contains a band of frequencies, each frequency has a different energy. This means that the response of buildings to earthquakes depends not only on the intensity of the earthquake but on its frequency content as well. In this study, two different approaches have been used: deterministic approach which is the time history analysis to show how the intensity of earthquakes affects the building response, and the nondeterministic random vibration approach, which is to clarify the response in the frequency domain and to show the effect of dominant frequencies of the earthquake. Both a prototype and a 1:6 scaled model was used to simulate a two-story steel building. In the experiential part, a shaking table was used to simulate a 1:6 scaled El-Centro 1940 NS earthquake as a base excitation with different intensities (0.05, 0.15, and 0.32g). In the theoretical part, Abaqus software was adopted to simulate the numerical model of the building. The results showed that the deterministic approach may be a non-conservative approach.

Keywords

• stationary random vibration analysis
• time history analysis
• earthquake excitation