Modal Analysis, Experimental Validation, and Calibration of a Historical Masonry Minaret
Modal Analysis, Experimental Validation, and Calibration of a Historical Masonry Minaret
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历史砖石尖塔的模态分析、实验验证和校准
DOI：
10.1520/jte101677
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
N. Coşkun
中科院分区：
文献类型：
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作者：
A. Bayraktar;A. Altunışık;B. Sevim;T. Türker;M. Akköse;N. Coşkun
本文介绍了一座历史砖石尖塔的有限元建模、模态试验和有限元模型的标定。位于土耳其特拉布宗市中心的伊斯肯德帕萨历史砖石尖塔被选为应用。模态分析进行开发的3-D有限元模型的尖塔，以获得分析频率和振型。对宣礼塔进行了交通荷载和风等环境激励下的环境振动试验。通过在频域中对平均归一化功率谱密度进行峰值拾取和在时域中进行随机子空间识别，实现了仅输出模态参数的识别。动态特性，如固有频率，模态振型和阻尼比的确定。通过改变材料特性和边界条件等不确定的建模参数，对尖塔的有限元模型进行了标定，以最大限度地减小分析和实验估计模态特性之间的差异。在研究结束时，自然频率的最大差异平均从27%减少到5%。模型标定后，分析和实验的固有频率和振型之间也发现了很好的协议。
This paper describes a historical masonry minaret, its finite element modeling, modal testing, and finite element model calibration. Iskenderpasa 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.