Abstract
Non-destructive methods of structural testing are preferred to identify their current state because they do not damage the structure. Modal analysis is one of these methods that can be used for a comprehensive assessment of structural measurements. Its main advantage is that it can be used for variety applications. The paper presents an application of operational modal analysis to determine modal parameters of a laboratory steel truss structure. Its goal is to make contribution to the still unfinished development of modal analysis in the area of comprehensive application. There is important to try to use it and especially try to derive some basic generally applicable rules. It is an important step for experimental modal analysis before it can be widely used and accepted in engineering applications.
Highlights
When applying classical techniques of experimental operational analysis (EMA) to large constructions such as bridges and buildings, we encounter the problem of choosing an efficient excitation source [1]
The special technique described in [6] was used to join the individual measurements for Subspace Identification method (SSI)-COV method and the non-parametric assembly approach described in [10] was used for Frequency Domain Decomposition (FDD) method
A comparison of the resulting natural frequencies in Table 1 shows that similar results are obtained for both methods and the frequency difference is less than 1%
Summary
When applying classical techniques of experimental operational analysis (EMA) to large constructions such as bridges and buildings, we encounter the problem of choosing an efficient excitation source [1]. The requirements for excitation sources are so great that it is not technically feasible, or the cost of the excitation device is extreme [2] For this reason, operational modal analysis (OMA) techniques are used [3]. FDD is a modal analysis technique which generates a system realization using the frequency response given multi-output data. In FDD identification, the first step is to estimate the PSD matrix at discrete frequencies ω = ωi. The state transition matrix A is obtained from the shift invariance property of O, namely as the least squares solution of. These two matrices A and C are used to compute modal parameters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
