Numerical simulation of shaking table tests on 3D reinforced concrete structures

Bayhan, Beyhan Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.2

The current paper presents the numerical blind prediction of nonlinear seismic response of two full-scale, three dimensional, one-story reinforced concrete structures subjected to bidirectional earthquake simulations on shaking table. Simulations were carried out at the laboratories of LNEC (Laboratorio Nacional de Engenharia Civil) in Lisbon, Portugal. The study was motivated by participation in the blind prediction contest of shaking table tests, organized by the challenge committee of the 15th World Conference on Earthquake Engineering. The test specimens, geometrically identical, designed for low and high ductility levels, were subjected to subsequent earthquake motions of increasing intensity. Three dimensional nonlinear analytical models were implemented and subjected to the input base motions. Reasonably accurate reproduction of the measured displacement response was obtained through appropriate modeling. The goodness of fit between analytical and measured results depended on the details of the analytical models.

LabVIEW-based Remote Laboratory Experiments for a Multi-mode Single-leg Converter

Bayhan, Sertac The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

This study presents the design and implementation of a web-based remote laboratory for a multi-mode single-leg power converter, which is a topic in advanced power electronics course. The proposed laboratory includes an experimental test rig with a multi-mode single-leg power converter and its driver circuits, a measurement board, a control platform, and a LabVIEW-based user interface program that is operated in the server computer. Given that the proposed web-based remote laboratory is based on client/server architecture, the experimental test rig can be controlled by a client computer with Internet connection and a standard web browser. Although the multi-mode single-leg power converter can work at four different modes (main boost, buck-boost, boost-boost, and battery boost modes), only the buck-boost mode is used in the experiment because of page limit. Users can choose the control structure, control parameters, and reference values, as well as obtain graphical results from the user interface software. Consequently, the feedbacks received from students who conducted remote laboratory studies indicate that the proposed laboratory is a useful tool for both remote and traditional education.

Numerical simulation of shaking table tests on 3D reinforced concrete structures

Beyhan Bayhan 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.2

The current paper presents the numerical blind prediction of nonlinear seismic response of two full-scale, three dimensional, one-story reinforced concrete structures subjected to bidirectional earthquake simulations on shaking table. Simulations were carried out at the laboratories of LNEC (Laboratorio Nacional de Engenharia Civil) in Lisbon, Portugal. The study was motivated by participation in the blind prediction contest of shaking table tests, organized by the challenge committee of the 15th World Conference on Earthquake Engineering. The test specimens, geometrically identical, designed for low and high ductility levels, were subjected to subsequent earthquake motions of increasing intensity. Three dimensional nonlinear analytical models were implemented and subjected to the input base motions. Reasonably accurate reproduction of the measured displacement response was obtained through appropriate modeling. The goodness of fit between analytical and measured results depended on the details of the analytical models.

LabVIEW-based Remote Laboratory Experiments for a Multi-mode Single-leg Converter

Sertac Bayhan 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

This study presents the design and implementation of a web-based remote laboratory for a multi-mode single-leg power converter, which is a topic in advanced power electronics course. The proposed laboratory includes an experimental test rig with a multi-mode single-leg power converter and its driver circuits, a measurement board, a control platform, and a LabVIEW-based user interface program that is operated in the server computer. Given that the proposed web-based remote laboratory is based on client/server architecture, the experimental test rig can be controlled by a client computer with Internet connection and a standard web browser. Although the multi-mode single-leg power converter can work at four different modes (main boost, buck?boost, boost?boost, and battery boost modes), only the buck?boost mode is used in the experiment because of page limit. Users can choose the control structure, control parameters, and reference values, as well as obtain graphical results from the user interface software. Consequently, the feedbacks received from students who conducted remote laboratory studies indicate that the proposed laboratory is a useful tool for both remote and traditional education.

Variations in the hysteretic behavior of LRBs as a function of applied loading

Ozdemir, Gokhan,Bayhan, Beyhan,Gulkan, Polat Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.1

The study presented herein focused on the change in hysteretic force-deformation behavior of lead rubber bearings (LRBs). The material model used to idealize response of LRBs under cyclic motion is capable of representing the gradual attrition in strength of isolator unit on account of lead core heating. To identify the effect of loading history on the hysteretic response of LRBs, a typical isolator unit is subjected to cyclic motions with different velocity, amplitude and number of cycles. Furthermore, performance of an LRB isolated single degree of freedom system is studied under different seismic input levels. Finally, the significance of lead core heating effect on LRBs is discussed by considering the current design approach for base isolated structures. Results of this study show that the response of an LRB is governed strongly by the amplitude and number of cycles of the motion and the considered seismicity level.

Variations in the hysteretic behavior of LRBs as a function of applied loading

Gökhan Özdemir,Beyhan Bayhan,Polat Gülkan 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.1

The study presented herein focused on the change in hysteretic force-deformation behavior of lead rubber bearings (LRBs). The material model used to idealize response of LRBs under cyclic motion is capable of representing the gradual attrition in strength of isolator unit on account of lead core heating. To identify the effect of loading history on the hysteretic response of LRBs, a typical isolator unit is subjected to cyclic motions with different velocity, amplitude and number of cycles. Furthermore, performance of an LRB isolated single degree of freedom system is studied under different seismic input levels. Finally, the significance of lead core heating effect on LRBs is discussed by considering the current design approach for base isolated structures. Results of this study show that the response of an LRB is governed strongly by the amplitude and number of cycles of the motion and the considered seismicity level.

Knowledge and Attitudes about Human Papillomaviruses and Immunization among Turkish Pediatricians

Ozsurekci, Yasemin,Oncel, Eda Karadag,Bayhan, Cihangul,Celik, Melda,Ozkaya-Parlakay, Aslinur,Arvas, Mehmet,Ceyhan, Mehmet Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background: Human papillomavirus (HPV) is one of the most common sexually transmitted infectious agents, and the effectiveness of vaccine delivery programs will depend largely upon whether providers recommend vaccines. The objectives of this study were to examine pediatrician characteristics, knowledge, and attitudes associated with HPV and HPV immunization. Materials and Methods: Attendees of the national pediatric meeting in 2011, were asked to complete a questionnaire that, aside from demographic information, elicited level of agreement with statements regarding HPV, its related diseases, and HPV vaccination. It also documented attitudes and beliefs about HPV vaccination. Results: Of the 480 attendees, 226 (47%) filled in the questionnaire. The level of pediatrician HPV-related knowledge varied. The majority (78%) were aware that HPV infection is the most common sexually transmitted infection, while 51% were unaware that a condom is ineffective protection against HPV infection. Between 60-80% of respondents were aware of the effectiveness of HPV vaccination for women. On the other hand, only 10% were aware of reasons why men should be vaccinated against HPV. The majority (75%) of Turkish pediatricians were likely to recommend HPV vaccination to their daughter, if they had one. Seventy percent of pediatricians agreed that the HPV vaccination should be added to the National Immunization Program (NIP) in Turkey. However, the respondents documented concerns about the cost of the vaccination. Conclusions: Increasing pediatricians' knowledge and awareness of HPV and HPV vaccination may assist with the implementation of an effective NIP.