Journal Of Testing And Evaluation, cilt.36, sa.6, ss.516-524, 2008 (SCI-Expanded)
This paper
describes a historical masonry minaret, its finite element modeling, modal
testing, and finite element model calibration. İskenderpaşa historical masonry
minaret located in Trabzon City Center, Turkey, is selected as an application.
Modal analysis is performed on the developed 3-D finite element model of the
minaret to obtain the analytical frequencies and mode shapes. The ambient
vibration tests on the minaret under environmental excitations, such as traffic
loads and wind, are conducted. The output-only modal parameter identification
is carried out by using peak picking of the average normalized power spectral
densities in the frequency domain and stochastic subspace identification in the
time domain. Dynamic characteristics such as natural frequencies, mode shapes,
and damping ratios are determined. The finite element model of the minaret is
calibrated to minimize the differences between analytically and experimentally
estimated modal properties by changing some uncertain modeling parameters such
as material properties and boundary conditions. At the end of the study,
maximum differences in the natural frequencies are reduced on an average from
27 % to 5 %. A good agreement is also found between analytical and experimental
natural frequencies and mode shapes after model calibration.