Browsing by Author "Bagci M."
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Item Determination of the steady state response of viscoelastically supported rectangular specially orthotropic plates with varying supported area(2004) Altintas G.; Bagci M.The influence of the amount of the supported area on the free and forced vibration properties of anisotropic plate is presented. Using the energy based finite difference method, the problem is modelled by a kind of finite difference element. Due to the significiance of the fundamental frequency of the plate, its variation was investigated with respect to the amount of the supported area on the plate, mechanical properties of plate material and translational spring coefficient of supports. The steady state response of viscoelastically supported plates was also investigated numerically for various damping coefficients and amounts of supported areas. Numerical results are obtained to investigate the effect of the ratio of the plate system. In the numerical examples, the natural frequency parameters and steady state responses to a sinusoidally varying force are assessed for the fundamental mode. Results showing effect of supported area ratios of plate indicate that variation of ratio of supported area of plate system is very significiant. Convergence studies are made. Many new results have been presented. Considered problems are solved within the frame work of Kirchhoff-Love hypothesis.Item Capacity determination of steel frame systems according to artifical neural network analysis(CI-Premier Pte Ltd, 2011) Erdem R.T.; Seker S.; Gücüyen E.; Bagci M.Many damages and losses have been occurred after the major scaled earthquakes. Researches have been developed in structural engineering along with other engineering fields with parallel to scientific developments. Determination of collapse safeties of buildings is one of the most efficient ways to observe the behavior of them. Artificial neural networks are computing systems that simulate the biological neural systems of the human brain. Neural Networks types are widely used for engineering problems. Artificial neural network analysis is known as a complex system of the neurons that are connected each other with different influence level. It is composed of a large number of highly interconnected neurons working in unison to solve specific problems. The approach is based on biological models of the human brain's functions. Computation is modeled as a large network of interconnected simple processors and artificial neural network analysis can be trained to recognize input patterns and produce appropriate output responses. The problems that have sufficient training data are suitable for artificial neural network analysis. Prediction of the complex problems and fast evaluation of new examples are the mainly advantages of artificial neural network analysis. In this study, forty steel frame systems which have constant span length and story height are analysed. Earthquake loads are calculated for the frame systems and capacity curves are obtained by using SAP2000 analysis program. The results are evaluated by artificial neural network analysis. The database includes thirty two frames data for training and eight ones for testing the network. Finally the results are compared and given in figures. Suggestions are also proposed.Item Structural behaviour of steel lattice towers under wind loads(CI-Premier Pte Ltd, 2011) Seker S.; Erdem R.T.; Gücüyen E.; Bagci M.Latticed steel towers are used widely in a variety of civil engineering applications. In this paper, structural behavior of 50 and 75 meters lattice towers which are made of L sectioned frame members under 160km/h wind velocity that causes wind force into structure and have 10m2 square antenna area are investigated. The structures (160-10-50, 160-10-75) are handled in two types as space truss composed of pin-jointed (Model A) and rigid main legs surround space truss composed of pin-jointed (Model B). Wind force is based on Gust Factor and calculated according to EIA-TIA 222-F (Structural Standards Abstract for Steel Antenna Towers & Antenna Supporting Structures) code. The aim of this study is obtaining the effective periods, mass sources, inter story drift ratios, maximum displacements of peak points and maximum frame forces of four structures which have different joint connections and height to determine the safety of them.Item Strengthening of Rc beams with prefabricated RC rectangular cross-sectional plates(Association for Scientific Research, 2011) Tekin M.; Demir A.; Turali T.; Nohutçu H.; Bagci M.The topic of this study is to strengthen cracked beams with prefabricated RC rectangular cross-sectional plates. The damaged beams were repaired by epoxy based glue. The repaired beams were strengthened using prefabricated RC rectangular crosssectional plates. The strengthening plates were bonded to the bottom face of the beams by anchorage rods and epoxy. The strengthened beams were incrementally loaded up to maximum load capacities. The experimental results were satisfactory since the load carrying capacities of damaged beams were increased approximately 47% due to strengthening. The post-elastic strength enhancement and the displacement ductility of all the beams are researched during the experiments. The experimental program was supported by a three-dimensional nonlinear finite element analysis. The experimental results were compared with the results obtained from the beam modeled with ANSYS finite element program. © Association for Scientific Research.Item The behavior of masonry walls with reinforced plaster mortar(2013) Basaran H.; Demir A.; Bagci M.The purpose of this study is the improvement of the behaviors of walls constructed with masonry bricks using reinforced plaster mortars. In this study, 400 × 400 × 100 mm sized walls were constructed using 1: 2 scaled 100 × 50 × 30 mm sized masonry bricks. The walls were plastered using normal and various proportions of polypropylene and steel fiber reinforced plaster mortars and were subjected to vertical loads at 30°, 45°, 60°, and 90° angles. As a result of the experiments, attempts were made to present the strength, stiffness, and ductility of all of the walls. At the end of the study, an evaluation concerning failure envelope curve (σ - τ) obtained from test results according to plastered masonry walls types was performed. © 2013 Hakan Basaran et al.Item Strengthening of RC beams with prefabricated RC U cross-sectional plates(Techno-Press, 2014) Demir A.; Tekin M.; Turali T.; Bagci M.The topic of this study is to strengthen cracked beams with prefabricated RC U cross-sectional plates. The damaged beams were repaired by epoxy based glue. The repaired beams were strengthened using prefabricated plates. The strengthening plates were bonded to the bottom and side faces of the beams by anchorage rods and epoxy. The strengthened beams were incrementally loaded up to maximum load capacities. The experimental results were satisfactory since the load carrying capacities of damaged beams were increased approximately 76% due to strengthening. It was observed that strengthening plates had a dominant effect on the performance of beams in terms of both the post-elastic strength enhancement and the ductility. The experimental program was supported by a three-dimensional nonlinear finite element analysis. The experimental results were compared with the results obtained from the beam modeled with ANSYS finite element program. Copyright © 2014 Techno-Press, Ltd.Item Shaking table study of masonry buildings with reinforced plaster; [Ispitivanje zidanih gradevina s armiranom žbukom na vibracijskom stolu](Union of Croatian Civil Engineers and Technicians, 2014) Ba̧aran H.; Demir A.; Bagci M.; Ercan E.The objective of this study is to determine seismic behaviour of masonry buildings with reinforced plaster mortar, with a particular focus on the modification of structural response due to application of the polypropylene and steel reinforced plaster, as compared to an ordinary type of plaster. The resistance of one-storey single-span masonry buildings subjected to seismic load on the shaking table is investigated in the study. Experimental results revealed natural periods, response acceleration spectrums, and spectrum interactions of masonry buildings. In addition, finite element models of test buildings were established, and their results were compared with those obtained during experimental study.Item RC beam strengthening using precast RC plate bonding technique; [Ojačanje ab greda tehnikom povezivanja s predgotovljenom ab pločom](Union of Croatian Civil Engineers and Technicians, 2015) Demir A.; Bagci M.; Tekin M.; Nuhoglu A.The behaviour of RC beams strengthened with precast RC plates of rectangular and U cross-section is studied in the paper. An experimental investigation was conducted to assess effectiveness of strengthening with precast plates. The investigation was supported with the 2-D nonlinear finite element analysis (NLFEA). The NLFEA results showed agood level of correlation with test results. The proposed technique is considered to be a good alternative to RC jacketing and the technique is practical, economical and reliable for buildings or bridges with a greater number sisof similar beams.Item The Real-World Experience With Single Agent Ibrutinib in Relapsed/Refractory CLL(Elsevier Inc., 2022) Akpinar S.; Dogu M.H.; Celik S.; Ekinci O.; Hindilerden I.Y.; Dal M.S.; Davulcu E.A.; Tekinalp A.; Hindilerden F.; Ozcan B.G.; Hacibekiroglu T.; Erkurt M.A.; Bagci M.; Namdaroglu S.; Korkmaz G.; Bilgir O.; Cagliyan G.A.; Ozturk H.B.A.; Serin I.; Tiryaki T.O.; Ozatli D.; Korkmaz S.; Ulas T.; Eser B.; Turgut B.; Altuntas F.Introduction/Background: The emergence of novel agents targeting the B-cell receptor pathway and BCL-2 has significantly changed the therapeutic landscape of CLL. We evaluated the safety and efficacy of single-agent ibrutinib in relapsed/refractory CLL in real-world settings. Patients/Methods: A total of 200 relapsed/refractory CLL patients with a median age of 68 were included in this retrospective, multicenter, non-interventional study. Data of the study were captured from the patient charts of the participating centers. Results: The median for lines of previous chemotherapy was 2 (1-6); 62 (31.8%) patients had del17p and/or p53 mutations (del17p+/p53mut). Of the study group, 146 (75%) patients achieved at least PR, while 16 (8.7%) patients discontinued ibrutinib due to TEA. The most common drug-related adverse events were neutropenia (n: 31; 17.4%) and thrombocytopenia (n: 40; 22.3%), which were ≥ grade 3 in 9 (5%) and 5 (3.9%) patients, respectively. Pneumonia (n: 42; 23.7%) was the most common nonhematologic TEA. Atrial fibrillation (n: 5; 2.8%) and bleeding (n: 11; 6.3%) were relatively rare during the study period. Within a median follow-up period of 17 (1-74) months, 42 (21%) patients died. The estimated median OS of the study cohort was 52 months. Only the response to ibrutinib (CR/PR vs. SD/PD) was significantly associated with OS. Conclusion: Our results indicate good safety and efficacy for single-agent ibrutinib in R/R CLL in daily practice. © 2021 Elsevier Inc.Item The clinicopathological features and survival of Castleman disease: A multicenter Turkish study(Verduci Editore s.r.l, 2022) Yildiz J.; Bagci M.; Sayin S.; Kaya A.; Yilmaz F.; Ekinci O.; Dal M.S.; Basturk A.; Aydogdu I.; Albayrak M.; Dogan A.; Erkurt M.A.; Korkmaz S.; Ulas T.; Eser B.; Altuntas F.Objective: In this study, we aimed to investigate the clinicopathological features and survival of CD, which is quite rare and has many unknowns. Patients and Methods: This study was conducted by retrospectively evaluating patients diagnosed with CD in six different centers in Turkey. Results: The median age of 33 patients included in the study was 49 and 51.5% (n = 17) of these patients were women. 18 (54.5%) patients were in the hyaline vascular subtype and most of the patients were UCD (n = 20, 60.6%). The most common involvement region was head and neck (n = 19, 57.5%). The UCD group was younger than the MCD group (p=0.027). Visceral lymph node involvement was higher in MCD than in UCD (p=0.001). Similarly, it was observed that there was more hepatomegaly (p=0.035) and splenomegaly (p=0.013) in the MCD group. During the median 19.5 months follow-up period, there were no patients who died. Conclusions: It was observed that UCD and MCD are different clinical entities. Promising survival times can be achieved with surgical and systemic treatments in both subtypes of this extremely rare disease. However, this result should be supported by well-designed prospective comprehensive studies. © 2022 Verduci Editore s.r.l. All rights reserved.