Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026Scopus SJRQ1/r/bayburt/11537
  Modal parameter determination and structural assessment of historical minaret under earthquake and wind loads

  Yanik, Yusuf; Demirtaş, Betül; Yurdakul, Muhammet; Aymelek, Abdullah; Türker, Temel

  This study presents a comprehensive linear time history of a historical masonry minaret called the Grand Mosque Minaret in Bayburt, employing a finite element (FE) model subjected to five distinct real earthquake acceleration records. Ambient vibration tests were conducted within the framework of operational modal analysis (OMA), utilizing enhanced frequency domain decomposition technique to estimate the experimental modal parameters. The FE model, developed under the assumption of linear elastic material behavior, was updated through a vibration-based model updating technique to accurately represent the dynamic characteristics of the structure. Each seismic record was applied as a base excitation, and the corresponding time-dependent structural responses were computed for initial and updated FE models. The analysis yielded critical engineering parameters, including maximum displacement and minimum–maximum principal stress distributions. The results obtained from the FE analyses were evaluated comparatively. Also in this study, the wind loads of the minaret were determined using the TS 498 standard, and structural wind load analyses were performed on the initial and updated FE models. Drift ratio values of the minaret were calculated for earthquake records and wind loads, and the structural performance of the minaret was evaluated comparatively for both models. It has been found that the structural behavior of the minaret was significantly affected by earthquakes. The drift ratio values remained within the controlled damage limit for wind analyses, while earthquake analyses indicated that the minaret was mostly in the collapse limit. The results show that more effective conservation and restoration strategies for cultural heritage structures can be developed by using both FE and experimental methods.

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• MakaleYalnız künye2024Scopus SJRQ1/r/bayburt/10892
  Variations of natural frequencies of masonry minarets due to environmental effects

  Yanik, Yusuf; Aymelek, Abdullah; Yildirim, Ömer; Demirtaş, Betül; Türker, Temel

  It is very important to distinguish the reason of change in natural frequencies of structures either caused by a possible damage or environmental conditions (temperature and humidity). In this study, the changes in the dynamic properties of masonry and reinforced concrete minarets under environmental effects, such as temperature and humidity, were investigated. The masonry minarets of İskenderpaşa, Hacı Kasım, and Tavanlı Mosques and the reinforced concrete minarets of Karadeniz Technical University, Dilaveroğlu and Papatya Mosques in Trabzon were monitored by ambient vibration test method, and the relationship between natural frequencies and temperature and humidity was tried to be determined. For this purpose, the natural frequencies of these minarets were measured at certain intervals under different temperature and humidity conditions over a period of approximately 6 months. The vibration measurement system which was developed by our research team was used in the measurements. From the data collected by these measurements, the variation intervals of the natural frequencies (the smallest and the highest values), the percentages of change and their relations with temperature and humidity were revealed. This relationship was determined using linear–non-linear simple and multiple regression analyses. From this study, it was found that the natural frequencies change under environmental effects, such as temperature and humidity, and this rate of change was approximately 7%. There was moderate correlation in Tavanlı, Dilaveroğlu, and Papatya Minarets, and strong correlation in Hacı Kasım Minaret.

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• MakaleAçık Erişim2021Scopus SJRQ1/r/bayburt/12097
  Modal identification and fatigue behavior of Eynel steel arch highway bridge with calibrated models

  Sunca, Fezayil; Ergün, Mustafa; Altunişik, Ahmet Can; Günaydin, Murat; Okur, Fatih Yesevi

  In this paper, modal parameters of the Eynel steel arch highway bridge are identified and the fatigue behavior of the bridge is investigated. Modal parameters were extracted from three ambient vibration tests carried out over the period since the bridge came into service. The bridge became operational in 2009, and experimental measurements were taken in 2010, 2019, and 2021. The Enhanced Frequency Domain Decomposition (EFDD) method in the frequency domain and the Stochastic Subspace Identification (SSI) method in the time domain were used. Modal parameters were compared and any differences found over time in the measurement test results were investigated. Comparison of the results shows that changes in the natural frequencies were very limited and there was no change between the mode shapes. When experimental natural frequencies were compared, the maximum difference between the first and second measurements was calculated as 2.827%. Similarly, the maximum difference between the first and third measurements was 5.587% for the second mode, and around 3% for the other modes. This result is as expected because: (i) the bridge is not subject to heavy vehicle traffic and only connects village roads; (ii) no significant earthquake occurred during this period in the region which might have caused structural damage; (iii) no corrosion was found in the structural system elements as there was no contact with the reservoir water; (iv) no settlement or sliding occurred in the ground and boundary conditions remained unchanged. Moreover, the fatigue behavior of the bridge was investigated using the stress life method and AASHTO LRFD Bridge Design Specifications. To rationalize the results against the fatigue effects, the verified finite element model was used. From the fatigue analyses, it was concluded that the fatigue life of the bridge was within safe limits.

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  AtıfScopus16·WoS16·OpenAlex16

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