000013122 001__ 13122
000013122 005__ 20161114160328.0
000013122 04107 $$aeng
000013122 046__ $$k2009-06-22
000013122 100__ $$aDe Roeck, G.
000013122 24500 $$aExploring the limits and extending the borders of structural health monitoring

000013122 24630 $$n2.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013122 260__ $$bNational Technical University of Athens, 2009
000013122 506__ $$arestricted
000013122 520__ $$2eng$$aStructural health monitoring by vibration monitoring has been and still is a popular research topic. Especially the good results of state-of-the-art system identification methods applied to ambient vibration data has encouraged ongoing research in this field. Many - claimed to be new - methods are proposed which are often just variants of existing methods or which only work on noiseless numerically simulated data. The same applies to the many methods that have been developed to identify damage from observed changes in the dynamic signature (e.g. modal properties). This paper will present a number of recent innovations to extend the borders of what is realistically feasible with the current methods. One important evolution is the consideration of the uncertainty on the extracted modal parameters, which can be due to the finite number of data samples, coloured excitation, nonstationary structural behaviour, mass loading, inherent non-linearities… It is crucial to estimate this uncertainty because it propagates in the subsequent damage assessment. An example of a steel transmitter mast will illustrate the determination of uncertainties of eigenfrequencies, damping factors and mode shapes when using the stochastic subspace identification method. Important factors, decisive whether or not a particular (small) damage can be detected, are the choice of sensors (type, sensitivity, location, number) and the covered frequency interval. Often, ambient measurements only deliver quantitatively good information of the lower modes. A way to extend the frequency interval is the use of a (rather small) artificial excitation source, extra to the ambient disturbances. An example of a footbridge will highlight the advantages of combined stochastic-deterministic system identification.

000013122 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013122 653__ $$aStructural health monitoring, vibration monitoring, combined stochasticdeterministic system identification, modal properties, damage assessment. Abstract. Structural health monitoring by vibration monitoring has been and still is a popular research topic. Especially the good results of state-of-the-art system identification methods applied to ambient vibration data has encouraged ongoing research in this field. Many - claimed to be new - methods are proposed which are often just variants of existing methods or which only work on noiseless numerically simulated data. The same applies to the many methods that have been developed to identify damage from observed changes in the dynamic signature (e.g. modal properties). This paper will present a number of recent innovations to extend the borders of what is realistically feasible with the current methods. One important evolution is the consideration of the uncertainty on the extracted modal parameters, which can be due to the finite number of data samples, coloured excitation, nonstationary structural behaviour, mass loading, inherent non-linearities… It is crucial to estimate this uncertainty because it propagates in the subsequent damage assessment. An example of a steel transmitter mast will illustrate the determination of uncertainties of eigenfrequencies, damping factors and mode shapes when using the stochastic subspace identification method. Important factors, decisive whether or not a particular (small) damage can be detected, are the choice of sensors (type, sensitivity, location, number) and the covered frequency interval. Often, ambient measurements only deliver quantitatively good information of the lower modes. A way to extend the frequency interval is the use of a (rather small) artificial excitation source, extra to the ambient disturbances. An example of a footbridge will highlight the advantages of combined stochastic-deterministic system identification.

000013122 7112_ $$aCOMPDYN 2009 - 2nd International Thematic Conference$$cIsland of Rhodes (GR)$$d2009-06-22 / 2009-06-24$$gCOMPDYN2009
000013122 720__ $$aDe Roeck, G.$$iReynders, E.
000013122 8560_ $$ffischerc@itam.cas.cz
000013122 8564_ $$s3186636$$uhttps://invenio.itam.cas.cz/record/13122/files/CD166.pdf$$yOriginal version of the author's contribution as presented on CD, section: Identification methods in structural dynamics - iii - (MS).
000013122 962__ $$r13074
000013122 980__ $$aPAPER