Experimental identification damping ratios of steel beam structures by Frequency Domain Decomposition (FDD) method

Abstract

Natural frequency, mode shape and damping ratio are important dynamic characteristics of building structures and can be determined by analytical or experimental methods. The natural frequency and mode shape can be accurately determined by dynamic tests on structures, while determining the damping ratio is often more complicated and the error is difficult to control. Calculating the damping ratio becomes extremely important in structural dynamics because the damping ratio is one of the important parameters of resonance. This article presents a theoretical and experimental method to identify the damping ratios of steel beam structures using the frequency domain decomposition (FDD) method. This method belongs to the
group of Operational Model Analysis method, which only uses response measurement data to determine the dynamic characteristics of the structure (natural frequency, mode shape, damping ratio).

Keywords: Natural frequency; mode shape; damping ratio; FDD.