Experimental work on seismic behavior of various types of masonry infilled RC frames

Misir, I. Serkan,Ozcelik, Ozgur,Girgin, Sadik Can,Kahraman, Serap Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.6

Reinforced concrete frame structures with masonry infill walls constitute the significant portion of the building stock in Turkey. Therefore it is very important to understand the behavior of masonry infill frame structures under earthquake loads. This study presents an experimental work performed on reinforced concrete (RC) frames with different types of masonry infills, namely standard and locked bricks. Earthquake effects are induced on the RC frames by quasi-static tests. Results obtained from different frames are compared with each other through various stiffness, strength, and energy related parameters. It is shown that locked bricks may prove useful in decreasing the problems related to horizontal and vertical irregularities defined in building codes. Moreover tests show that locked brick infills maintain their integrity up to very high drift levels, showing that they may have a potential in reducing injuries and fatalities related to falling hazards during severe ground shakings.

Exponential Approximations On Multiplicative Calculus

Emine Misirli,Ali Ozyapici 장전수학회 2009 Proceedings of the Jangjeon mathematical society Vol.12 No.2

A new kind of calculus, multiplicative calculus, was developed and the de…nition of a new kind of derivative was given within this calculus. Multiplication and division, in this calculus, take the role of summation and di¤erence in the ordinary calculus. Thus, multiplicative calculus is based on multiplicative rate of change, whereas the ordinary calculus is based on additive rate of change. In this manner, many functions can be represented by infinite product, analogous to the infinite sum, based on multiplicative derivative. These generate an idea for getting exponential approximations to functions.

Experimental work on seismic behavior of various types of masonry infilled RC frames

I. Serkan Misir,Ozgur Ozcelik,Sadik Can Girgin,Serap Kahraman 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.6

Reinforced concrete frame structures with masonry infill walls constitute the significant portion of the building stock in Turkey. Therefore it is very important to understand the behavior of masonry infill frame structures under earthquake loads. This study presents an experimental work performed on reinforced concrete (RC) frames with different types of masonry infills, namely standard and locked bricks. Earthquake effects are induced on the RC frames by quasi-static tests. Results obtained from different frames are compared with each other through various stiffness, strength, and energy related parameters. It is shown that locked bricks may prove useful in decreasing the problems related to horizontal and vertical irregularities defined in building codes. Moreover tests show that locked brick infills maintain their integrity up to very high drift levels, showing that they may have a potential in reducing injuries and fatalities related to falling hazards during severe ground shakings.

Experimental Cyclic Behavior of Precast Hybrid Beam-Column Connections with Welded Components

Girgin, Sadik Can,Misir, Ibrahim Serkan,Kahraman, Serap Korea Concrete Institute 2017 International Journal of Concrete Structures and M Vol.11 No.2

Post-earthquake observations revealed that seismic performance of beam-column connections in precast concrete structures affect the overall response extensively. Seismic design of precast reinforced concrete structures requires improved beam-column connections to transfer reversed load effects between structural elements. In Turkey, hybrid beam-column connections with welded components have been applied extensively in precast concrete industry for decades. Beam bottom longitudinal rebars are welded to beam end plates while top longitudinal rebars are placed to designated gaps in joint panels before casting of topping concrete in this type of connections. The paper presents the major findings of an experimental test programme including one monolithic and five precast hybrid half scale specimens representing interior beam-column connections of a moment frame of high ductility level. The required welding area between beam bottom longitudinal rebars and beam-end plates were calculated based on welding coefficients considered as a test parameter. It is observed that the maximum strain developed in the beam bottom flexural reinforcement plays an important role in the overall behavior of the connections. Two additional specimens which include unbonded lengths on the longitudinal rebars to reduce that strain demands were also tested. Strength, stiffness and energy dissipation characteristics of test specimens were investigated with respect to test variables. Seismic performances of test specimens were evaluated by obtaining damage indices.

Performance evaluation of suspended ceiling systems using shake table test

Ozgur Ozcelik,Ibrahim S. Misir,Serhan Saridogan 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.1

The national standard being used in Turkey for suspended ceiling systems (SCS) regulates material and dimensional properties but does not contain regulations regarding installation instructions which cause substandard applications of SCSs in practice. The lack of installation instructions would potentially affect the dynamic performance of these systems. Also, the vast majority of these systems are manufactured using substandard low-quality materials, and this will inevitably increase SCS related damages during earthquakes. The experimental work presented here focuses on the issue of dynamic performance of SCSs with different types of carrier systems (lay-on and clip-in systems), different weight conditions, and material-workmanship qualities. Moreover, the effects of auxiliary fastening elements, so called seismic perimeter clips, in improving the dynamic performance of SCSs were experimentally investigated. Results show that clip-in ceiling system performs better than lay-on system regardless of material and workmanship qualities. On the other hand, the quality aspect becomes the most important parameter in affecting the dynamic performance of lay-on type systems as opposed to tile weights and usage of perimeter clips. When high quality system is used, tile weight does not change the performance of lay-on system, however in poor quality system, tile weight becomes an important factor where heavier tiles considerably decrease the performance level. Perimeter clips marginally increase the dynamic performance of lay-on ceiling system, but it has no effect on the clip-in ceiling system under the shaking levels considered.

Experimental Cyclic Behavior of Precast Hybrid Beam-Column Connections with Welded Components

Sadik Can Girgin,Ibrahim Serkan Misir,Serap Kahraman 한국콘크리트학회 2017 International Journal of Concrete Structures and M Vol.11 No.2

Post-earthquake observations revealed that seismic performance of beam-column connections in precast concrete structures affect the overall response extensively. Seismic design of precast reinforced concrete structures requires improved beamcolumn connections to transfer reversed load effects between structural elements. In Turkey, hybrid beam-column connections with welded components have been applied extensively in precast concrete industry for decades. Beam bottom longitudinal rebars are welded to beam end plates while top longitudinal rebars are placed to designated gaps in joint panels before casting of topping concrete in this type of connections. The paper presents the major findings of an experimental test programme including one monolithic and five precast hybrid half scale specimens representing interior beam-column connections of a moment frame of high ductility level. The required welding area between beam bottom longitudinal rebars and beam-end plates were calculated based on welding coefficients considered as a test parameter. It is observed that the maximum strain developed in the beam bottom flexural reinforcement plays an important role in the overall behavior of the connections. Two additional specimens which include unbonded lengths on the longitudinal rebars to reduce that strain demands were also tested. Strength, stiffness and energy dissipation characteristics of test specimens were investigated with respect to test variables. Seismic performances of test specimens were evaluated by obtaining damage indices.