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Öğe Investigation of plasma arc cutting parameters with type-2 fuzzy set and system(De Gruyter, 2013-10) Çelik, Yahya Hışman; Özek, Cebeli; Bulut Özek, MüzeyyenThe objective of the present study was it to design a type-2 fuzzy set and system in order to predict surface roughness and hardness depending on the parameters (material thickness, cutting speed, arc voltage and current) of the plasma arc cutting process of S235JR sheet materials. Therefore, some experimental studies were conducted. The experimentally determined data were used to describe the type-2 fuzzy set and system. Type-2 fuzzy set and system was found to be usefull to predict surface roughnes and hardness. According to the obtained values, the best surface roughness and the values closest to the hardness of the raw material were obtained at 1500 mm/min cutting speed, 8 mm material thickness, 115 V arc voltage and 80 A current.Öğe Delphi programlama dili kullanılarak plastik enjeksiyon kalıplarında ürün maliyet hesabı ve yeni bir paket programın geliştirilmesi(e-Journal of New World Sciences Academy, 2010-07) Çelik, Yahya Hışman; Özek, Cebeli; Gürgüze, GürkanBu çalışmada, plastik enjeksiyon kalıplama tekniklerini kullanarak kalıplanan plastik ürünlerin maliyet analizini hesaplayan yeni bir program geliştirilmiştir. Geliştirilen maliyet programı için Delphi programlama dili kullanılmıştır. Program, enjeksiyon kalıplama teknikleri ile üretilen bir adet plastik ürünün maliyeti için veri bilgi girişinden seçilen değerlere göre hesaplama yapmaktadır. Elde edilen bilgilere bağlı olarak ham plastik malzeme maliyeti, kalıp maliyetine bağlı amortisman gideri, soket giderleri, işleme ve işçilik giderleri analiz edilerek plastik ürünün tahmini maliyeti hesaplanmaktadır. Programın geçerliliğini kontrol etmek için araçlardaki hava üfleme elemanı örneği seçilmiştir. Programdan elde edilen değerler gerçek değerlerle karşılaştırılarak programın geçerliliği kontrol edilmiştir. Bu verilere bağlı olarak geliştirilen paket program ile gerçek değerler arasında yaklaşık %9,7 kadar bir fark olduğu görülmüştür.Öğe Plastik enjeksiyon kalıplarında enjeksiyon sürelerinin yapay sinir ağları ile modellenmesi(Fırat Üniversitesi, 2011) Çelik, Yahya Hışman; Özek, CebeliÖğe Investigation of turning in different cutting parameters of Al 6061 with finite elements method(Fırat Üniversitesi, 2017-10) Çelik, Yahya Hışman; Özek, Cebeli; Türkan, CihatIn this study, the effects of cutting parameters on cutting force, temperature and stress were investigated in the turning of 6061 aluminum alloy by using DEFORM-3D package program based on finite element method. Constant depth of cut (1 mm), three different cutting speeds (40, 60 and 80 m/min), and three different feed rates (0.05, 0.1 and 0.15 mm/rev) were used in research simulations. From the made analyses, the lowest cutting force was obtained as 150 N at 80 m/min cutting speed and 0.05 mm/rev feed rate, the highest cutting force was obtained as 368 N at 40 m/min cutting speed and 0.15 mm/rev feed rate. While the lowest temperature was obtained as 230 °C at 40 m/min cutting speed and 0.05 mm/rev feed rate, the highest temperature was obtained as 354 °C at 80 m/min cutting speed and 0.05 mm/rev feed rate. In addition, the lowest stress was 997 MPa at 80 m/min cutting speed and 0.05 mm/rev feed rate, the maximum stress was 1090 MPa at 40 m/min cutting speed and 0.15 mm/rev feed rate. It has been observed that the cutting force and the stress value show a similar tendency depending on the cutting parametersÖğe CNC plazma ile kesmede işleme parametrelerinin kesme kalitesine etkisinin araştırılması(Fırat Üniversitesi, 2011) Çelik, Yahya Hışman; Özek, CebeliNowadays, It is important to usenew machines in manufacturing technologies.Oneof the most important of these machinesisCNC plasma cutting machines. The measuring sensitivity is not soimportantinthese machines.However,the materials workingunder high pressure and strength can be cut by means of these machines. In thisstudy,S235JR sheet materials of 4, 6 and 8mm thickness which areused inpressurized containers were cut in the CNC plasma machine atvarious speeds, amperesand arc voltages. For Cutting processeswhichwerecarried out atvarious parameters,surface roughnessesand temperature distributionsweremeasured on the samplescut.Comments on the hardness and material strength of the material exposed to the cutting process were madedepending on surface roughnessesand temperature distributions.Öğe Investigate the effect of pre-drilling in friction drilling of A7075-T651(Taylor & Francis, 2014-04-28) Demir, Zülküf; Özek, CebeliFriction drilling is a non-traditional hole achieving method that is a clean, chip-less process, which is called thermal drilling, form drilling, flow drilling, and friction stir drilling. In this study pre-drilling friction drilling was investigated for improving the bushing shape of A7075-T651, which is a brittle cast material. During the process, surface roughness and bushing shapes were analyzed and generated frictional heat was measured by the virtue of thermocouples. Experiments were carried out to 4mm and 6mm in thicknesses of A7075-T651 aluminum alloy at 1200, 1800, 2400, 3000, and 3600 rpm spindle speeds, 20, 40, 60, 80, and 100 mm/min feed rates with using high-speed steel rotating conical tool, whose diameter is 8 mm. Consequently, the bushing shapes were advanced without cracks and petal formation in pre-drilling Friction drilling in comparison with without pre-drilling process. With increasing pre-drilled hole diameter the generated frictional heat was decreased. The achieved temperature was realized to be 1/2-1/3 of the melting temperature of the workpiece. Surface roughness values were decreased with decreasing or increasing both spindle speed and feed rate correspondingly.Öğe Calculating molding parameters in plastic injection molds with ANN and developing software(Taylor & Francis, 2012-02) Çelik, Yahya Hışman; Özek, CebeliIn recent years, plastic injection molds are widely used for producing products in various areas, such as aerospace, automotive, medical, electronics, and toys. The quality of these products depends on correctly chosen molding parameters. In this study, a new package program (NPP)-Software that calculates various injection molding parameters was developed to mold plastic products obtained by plastic injection molding techniques using the model of artificial neural network (ANN). The Delphi programming language was used in the develop the (NPP)-Software. The developed (NPP)-Software was trained and tested using the Levenberg–Marquardt (LM) algorithm, the ANN. One-thousand three-hunderd pieces of data were collected, out of which 250 were used to train the network. The ANN is employed to find optimum molding parameters that enable minimum defects in the injection-molded part, such as volumetric shrinkage, injection time, and cooling time. The three parameters predicted, using the (NPP)-Software, were compared using experimental results.Öğe An experimental investigation on bushing geometrical properties and density in thermal frictional drilling(Multidisciplinary Digital Publishing Institute (MDPI), 2018-12-18) Demir, Zülküf; Özek, Cebeli; Bal, MuhammedIn thermal friction drilling (TFD) operations, the geometrical dimensions of bushing shape, height and wall thickness are the most vital consequences, since these increase the connecting length and strength. In this paper, AA7075-T651 aluminum alloys with 2, 4, 6, 8, and 10 mm thicknesses were drilled with the TFD process in order to investigate density, volume ratio, and height and wall thickness of the bushings. The experiments were conducted at constant spindle speed and feed rate conditions by using High Speed Steel (HSS) conical tools of 5, 10, 15, and 20 mm in diameter. It was experimentally found that the bushing height and the wall thickness had a tendency to increase linearly with the increase in both material thickness and tool diameter. The effect of tool diameter was found to have more influence on the measurable values than the thickness of the drilled material. The density of the bushing changed trivially. Approximately 70-75 percent of the evacuated material formed the bushing shape in TFD operations.Öğe Plastik enjeksiyon kalıplarında kalıplama parametrelerinin bulanık mantık ile modellenmesi(Fırat Üniversitesi, 2011) Çelik, Yahya Hışman; Özek, CebeliIn this study, the elementof the internal threaded ½”-¾” plasticT elbow hasbeen molded at differentinjection pressures, mold temperaturesand molten plastic temperatures in aninjection machine. The amount of volumetric shrinkage, injection and cooling time obtained for this element which was molded at different parameters were investigated experimentally. The data obtained from experimental studyweredescribed to the Fuzzy LogicModel. According to the results which Fuzzy Logicproduced, itwas determined that with the increase of injection pressureand molten plastic temperature, injection time decreased, on the other hand, the amount of volumetric shrinkage and cooling time increased.With the increase ofmold temperature, it was determined that the amount of volumetric shrinkage decreased, but injection and cooling time increased.Öğe Effect of cutting parameters on workpiece and tool properties during drilling of Ti-6Al-4V(De Gruyter, 2016-05-23) Çelik, Yahya Hışman; Yıldız, Hakan; Özek, CebeliThe main aim of machining is to provide the dimensional preciseness together with surface and geometric quality of the workpiece to be manufactured within the desired limits. Today, it is quite hard to drill widely utilized Ti-6Al-4 V alloys owing to their superior features. Therefore, in this study, the effects of temperature, chip formation, thrust forces, surface roughness, burr heights, hole diameter deviations and tool wears on the drilling of Ti-6Al-4 V were investigated under dry cutting conditions with different cutting speeds and feed rates by using tungsten carbide (WC) and high speed steel (HSS) drills. Moreover, the mathematical modeling of thrust force, surface roughness, burr height and tool wear were formed using Matlab. It was found that the feed rate, cutting speed and type of drill have a major effect on the thrust forces, surface roughness, burr heights, hole diameter deviations and tool wears. Optimum results in the Ti-6Al-4 V alloy drilling process were obtained using the WC drill
