000020075 001__ 20075
000020075 005__ 20170118182353.0
000020075 04107 $$aeng
000020075 046__ $$k2017-01-09
000020075 100__ $$aBernagozzi, Giacomo
000020075 24500 $$aOn the Application of Output-Only Modal Identification To Base Excited Frame Structures

000020075 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000020075 260__ $$b
000020075 506__ $$arestricted
000020075 520__ $$2eng$$aThe work focuses on the application of modal identification techniques to plan-asymmetric building structures that are subjected to base excitation. The challenging problem related to the identification of high-order modes and, especially, torsional modes is taken into account for different lengths of time and directions of the applied base excitation. The evaluation of the identification accuracy was performed through a simulation approach: analytical models of planasymmetric RC frames, which are characterized by different structural eccentricities, were subjected to white noise base excitation. This kind of input is rather idealized for real buildings, which are generally excited by earthquake or traffic loads, but it is commonly adopted in experimental programs related to vibration-based damage detection using scaled or full-size buildings tested on shaking tables. The output-only modal identification was applied using the response timehistories only and the modal parameters, in terms of natural circular frequencies, modal damping ratios and mode shapes, were determined. These identified parameters were then compared with the true values related to the initially assumed analytical models. Firstly, the analyses were performed for one structural configuration, for a fixed direction of the applied base excitation, but considering various durations of such input. The results showed that the accuracy related to mode shapes identification was lower for the first torsional mode with respect to the second longitudinal mode, which is a higherorder mode. In addition, the identified torsional mode shape exhibited major modal complexity than the longitudinal mode, as a result of simulated noise and identification errors. Secondly, the analyses were conducted considering different structural configurations, a fixed duration of the base excitation, but different directions of the applied input. The outcomes showed that the accuracy in mode shape estimations, evaluated by calculating the Modal Assurance Criterion (MAC) between identified and analytical mode shapes, was strongly dependent on the direction of the applied input, especially for high-order modes. It was also observed that these MAC values are directly correlated with the modal participation factors of the structure, evaluated for the different directions of the base excitation. Referring to the torsional mode shapes, the results showed that the number of input directions, for which these modes can be identified, are higher for the structures with major structural eccentricities.

000020075 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000020075 653__ $$aoutput-only modal identification, plan-asymmetric buildings, base excited structures

000020075 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000020075 720__ $$aBernagozzi, Giacomo$$iLandi, Luca$$iDiotallevi, Pier Paolo
000020075 8560_ $$ffischerc@itam.cas.cz
000020075 8564_ $$s1302564$$uhttps://invenio.itam.cas.cz/record/20075/files/506.pdf$$yOriginal version of the author's contribution as presented on USB, paper 506.
000020075 962__ $$r16048
000020075 980__ $$aPAPER