M. Khanmohammadi - Associate Professor of Civil Engineering Faculty at University of Tehran, Tehran, Iran
M. Eshraghi - Graduated Student of Master of Science at University of Tehran, Tehran, Iran
s behboodi - Master of Science Student at University of Tehran, Tehran, Iran
m nafisifard - Master of Science Student at University of Tehran, Tehran, Iran

Structural dynamic characteristics including natural frequency, mode shapes, and damping are the most important parameters in determining the seismic response of any structure. The present study investigated the dynamic characteristics of a damaged four-story steel building at Sarpol-e Zahab province in two conditions by ambient vibration test. At the first condition, the building contained nonstructural elements while at the second condition, nonstructural elements of the third and the fourth story were eliminated. Experimental results indicate that nonstructural elements have significant effects on the building’s natural frequency and the damping.

Dynamic characteristics, nonstructural elements, Damping, Ambient Vibration Test