Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
3 results
Search Results
Master Thesis Impact Resistance of Steel Fiber Reinforced Concrete Slabs(Izmir Institute of Technology, 2015) Yaşayanlar, Süleyman; Saatcı, SelçukAs rare as it may seem, impact loads can act on a structure in its lifespan. For structures such as nuclear energy facilities, industrial facilities, and military buildings design for impact loads may be required. Steel fibers are increasingly used in the design and construction of such reinforced concrete structures. However, studies on the effect of steel fibers on the impact resistance of reinforced concrete structures are rare in the literature. This study investigates the global behavior of reinforced concrete slabs with different ratios of steel fibers under static and impact loading. 10 steel fiber reinforced concrete slabs with dimensions of 2150x2150x150 mm were tested with varying steel fiber volume ratios of 0.5 %, 1.0 % and 1.5 %. Specimens were manufactured as twins, as one to be tested under static loading and one to be tested under impact loading. Static tests were carried out by applying a static load at the midpoint with a hydraulic jack, whereas impact tests were applied through free falling drop-weights. Observed behavior and collected data were compared with companion studies of Batarlar (2013) and Arsan (2014), as they have used the same test setup with different parameters. As a result, it was seen that even steel a fiber addition of 0.5 % in volume was sufficient to provide a ductile behavior both under static and impact loading. Steel fibers significantly enhanced the impact behavior by increasing the strength and resiliency of the specimens.Master Thesis Behavior of Reinforced Concrete Slabs Subjeted To Impact Loads(Izmir Institute of Technology, 2013) Batarlar, Baturay; Saatcı, SelçukThis study presents the findings of an experimental program designed for investigating the behavior of RC slabs under low-velocity impact loads. Six RC slabs with dimensions 2015x2015x150 mm were tested at the Structural Laboratory of the Izmir Institute of Technology. To facilitate a comparison between the static and impact behavior of identical specimens, the slabs were cast in three identical pairs, such that one of the specimens was tested under impact loads whereas its identical twin was tested under static loads. To test the slabs under simply supported conditions, an innovative impact test setup was designed and manufactured, supporting the specimens at 20 locations along the perimeter and holding the specimens in place during the impact induced rebound. This setup was also used for the testing of the specimens under monotonically increasing static loads at the midpoint. Impact loads were induced on the specimens by a free falling drop-weight, impacting the specimens at the midpoint. The specimens were intensely instrumented with 20 load cells at each support location, 24 displacement transducers, 6 accelerometers and 12 strain gauges fixed to the reinforcing bars. Dynamic data was captured with the help of a high speed data acquisition system, capturing and recording the data at a rate of 250 kHz per channel. The results obtained from these tests revealed that the impact behavior of slabs differs significantly compared to their static behavior. Displacement profiles and force distributions are highly affected due to the high inertia forces during the impact.Master Thesis Nonlinear Finite Element Analysis of Reinforced Concrete Structures Subjected To Impact Loads(Izmir Institute of Technology, 2010) Cağaloğlu, Neriman Çare; Saatcı, Selçuk; Saatcı, SelçukDesign of reinforced concrete structures against extreme loads, such as impact and blast loads, is increasingly gaining importance. However, due to the problem.s complicated nature, there exists no commonly accepted methodology or a design code for the analysis and design of such structures under impact loads. Therefore, engineers and researchers commonly resort to the numerical methods, such as the finite element method, and utilize different methods and techniques for the analysis and design. Although each method has its advantages and disadvantages, usually engineers and researchers persist on their method of choice, without evaluating the performance of other methods available. In addition, there is no significant study in the literature comparing the methods available that can guide the engineers and researchers working in the area. This study compares the performance of some numerical methods for the impact analysis and design with the help from actual impact test results in the literature. Computer programs VecTor2 and VecTor3 were selected for nonlinear finite element methodology, which were based on the Modified Compression Field Theory. Impact tests conducted on reinforced concrete beams were modeled and analyzed using these programs. Moreover, same beams were modeled also using a single degree of freedom spring system method. The results obtained from both approaches were compared with each other and the test results, considering their accuracy, computation time, and ease of use.