This paper reports on a study to determine the structural dynamic characteristics, such as natural frequencies, mode shapes and damping ratios, of timber mosques using ambient vibration tests after restoration. Kuşluca historical timber mosque in the Sürmene district of Trabzon, Turkey is selected as a case study. The mosque was built in the early twentieth century with two floors. Restoration projects were prepared in 2008 and the mosque was re-opened in 2011. A finite-element model of the mosque was constituted based on restoration drawings, and modal analysis was performed using orthotropic material properties. A literature review was used to determine the initial dynamic characteristics, such as natural frequencies, mode shapes and damping ratios. Non-destructive experimental measurements were conducted after construction to validate the numerical results using in situ tests. The first three natural frequencies were obtained numerically and experimentally. There was a close agreement between mode shapes, but 30% difference in natural frequencies. To minimise the differences, the finite-element model was updated using manual and automated updating procedures, changing uncertain parameters such as material properties, semi-rigid element connections, boundary conditions and section properties.

中文翻译：

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修复后的历史木材清真寺的环境振动测试和建模

本文报告了一项研究，旨在通过恢复后的环境振动测试来确定木材清真寺的结构动力学特性，例如固有频率，振型和阻尼比。案例研究选择了土耳其特拉布宗Sürmene区的Kuşluca历史木材清真寺。这座清真寺始建于20世纪初，楼高两层。于2008年准备了修复项目，并于2011年重新开放了该清真寺。根据修复图纸构造了该清真寺的有限元模型，并利用正交异性材料特性进行了模态分析。文献综述用于确定初始动态特性，例如固有频率，振型和阻尼比。施工后进行了无损实验测量，以使用原位测试验证数值结果。前三个固有频率是通过数值和实验获得的。振型之间有密切的一致性，但固有频率相差30％。为了使差异最小化，使用手动和自动更新程序更新了有限元模型，更改了不确定参数，例如材料属性，半刚性元素连接，边界条件和截面属性。