Yazar "Tarakcioglu, Necmettin" seçeneğine göre listele
Listeleniyor 1 - 12 / 12
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Burst failure load of composite pressure vessels(ELSEVIER SCI LTD, 2009) Onder, Aziz; Sayman, Onur; Dogan, Tolga; Tarakcioglu, NecmettinIn this study, optimal angle-ply orientations of symmetric and antisymmetric [0/-0](s) shells designed maximum burst pressure were examined. Burst pressure of filament wound composite pressure vessels under alternating pure internal pressure was investigated. The study deals with the influences of temperature and winding angle on filament Wound composite pressure vessels. Finite element method and experimental approaches were employed to verify the optimum winding angles. An elastic solution procedure based on Lekhnitskii's theory was developed in order to predict the burst failure pressure of the pressure vessels. The Tsai-Wu failure criterion, maximum strain and stress theories were applied for Verifying the burst failure pressure of tubes. The solution was presented and discussed for various orientation angles. Glass reinforced plastic (GRP) pipes were manufactured by E-glass-epoxy and tested for the closed-ended condition. Test specimens had four layers, which had various orientation angles. The layers were Oriented symmetrically and antisymmetrically for, [45 degrees/-45 degrees](s), [55 degrees/-55 degrees](s), [60 degrees/-60 degrees](s), [75 degrees/ -75 degrees](s) and [88 degrees/-88 degrees](s) orientations. For this study, a PLC controlled hydraulic pressure testing machine has been utilized. The hygrothermal and other mechanical properties were measured on E-glass-epoxy composite flat layers. Some analytical and experimental solutions were compared with the finite element solutions, in which commercial software ANSYS 10.0 Was utilized; close results were obtained between analytical and experimental solutions for some orientations. (C) 2008 Elsevier Ltd. All rights reserved.Öğe Damage behavior of filament winding pipes modified with carbon nanotubes under internal pressure(GAZI UNIV, 2015) Tasyurek, Mustafa; Tarakcioglu, NecmettinIn this study, damage behavior of filament winded glass-reinforced plastic (GRP) pipes that reinforcing material mixed in different proportions of under static internal pressure was examined. Multi-walled carbon nanotubes (MWCNT) are used as reinforcing material and the medium-viscosity epoxy are used as matrix material. Free-ended internal pressure test was applied to the experiment. Test specimens were produced with six layered and +/- 55 degrees winding angle. Reinforcement material was added as 0,5% and 1%. In addition, the wall thickness ratio of surface cracks on each kind of sample (w / t) was opened as 0.25 and 0.5 measure. Pure epoxy GRP pipes with same physical characteristics have been used as comparison sample. According to the geometry of the notch surface and different reinforcement ratios burst pressure values were determined and investigated.Öğe Determination of the mechanical, thermal and physical properties of nano-CaCO3 filled high-density polyethylene nanocomposites produced in an industrial scale(SAGE PUBLICATIONS LTD, 2016) Sepet, Harun; Tarakcioglu, Necmettin; Misra, R. D. K.The objective of this study is to examine the mechanical, thermal, and physical properties of industrially produced nano-CaCO3 filled high-density polyethylene nanocomposites. For this purpose, 1.0, 3.0, 5.0, 10.0, and 15.0wt.% loading of nano-CaCO3 filled high-density polyethylene nanocomposites were prepared by the melt mixing method using a compounder system, which consist of industrial banbury mixer, single screw extruder, and granule cutting. The effect of nano-CaCO3 on mechanical, thermal, and physical properties of nano-CaCO3/HDPE nanocomposites was investigated. As a result of all experiments, the tensile strength of nano-CaCO3 filled high-density polyethylene nanocomposite increased about 5% with addition of 1.0wt.% nano-CaCO3. But did not increase further as more nano-CaCO3 was added. The flexural strength of nano-CaCO3 filled high-density polyethylene nanocomposite increased about 4.5% with addition of 15.0wt.% nano-CaCO3.Then increased slightly as the nano-CaCO3 content increased to 15.0wt.%. The tensile and flexural modulus of high-density polyethylene were significantly improved after (from 1.0wt.% up to 15.0wt.%) addition of nano-CaCO3. The tensile elongation at break and shore D hardness was consistently decreased with the addition of nano-CaCO3. The nano-CaCO3 filled high-density polyethylene nanocomposites were determined to have lower impact energy level than neat high-density polyethylene. The occurred fracture areas with the impact were detected by scanning electron microscopy examination. It is understood that fracture surface morphology changes when nano-CaCO3 ratio increases. The fracture surface changes were examined to determine the fracture mechanism of nano-CaCO3 filled high-density polyethylene nanocomposites. Density, melting flow index, differential scanning colorimetry, and vicat softening temperature were used to characterize the physical and thermal properties of the nanocomposites. The X-ray diffraction, the fourier transform infrared spectrophotometry, the transmission electron microscopy, and the scanning electron microscopy were used to analyze the structural characteristics of the nanocomposites. It is concluded that the addition of the nano-CaCO3 in high-density polyethylene has significantly influenced the mechanical, thermal, and physical properties of the nanocomposites.Öğe Effect of inorganic nanofillers on the impact behavior and fracture probability of industrial high-density polyethylene nanocomposite(SAGE PUBLICATIONS LTD, 2018) Sepet, Harun; Tarakcioglu, Necmettin; Misra, R. D. K.The main purpose of this work is to study how the morphology of nanofillers and dispersion and distribution level of inorganic nanofiller influence the impact behavior and fracture probability of inorganic filler filled industrial high-density polyethylene nanocomposites. For this study, nanoclay and nano-CaCO3 fillers-high-density polyethylene mixings (0, 1, 3, 5wt.% high-density polyethylene) was prepared by melt-mixing method using a compounder system. The impact behavior was examined by charpy impact test, scanning electron microscopy, and probability theory and statistics. The level of the dispersion was characterized with scanning electron microscopy energy dispersive X-ray spectroscopy analysis. The results showed rather good dispersion of both of inorganic nanofiller, with a mixture of exfoliated and confined morphology. The results indicated that the impact strength of the industrial nanocomposite decreased with the increase of inorganic particulate content. The impact reliability of the industrial nanocomposites depends on the type of nanofillers and their dispersion and distribution in the matrix.Öğe The effect of weld line on tensile strength in a polymer composite part(SPRINGER LONDON LTD, 2016) Kagitci, Yusuf Caglar; Tarakcioglu, NecmettinWeld line problem which occurs in polymer parts produced by plastic injection method and affects appearance and strength on a large scale was researched in this paper. The three parameters affecting operation were called injection pressure, injection time, and packing pressure which influence the quality of weld line on the polymer products were researched. A joint which enables two different parts used in different places to be joined together and its subjection to a certain loan were discussed. Considering the usage area of the part, composite of glass fiber reinforced polyamide (PA 6 GFR 30) was chosen as the material, and the design process of the part was implemented. Samples were prepared by altering the determined injection parameters. Weld line of the produced samples were subjected to tensile strength test. Their structure parts were examined under the SEM, and the results were gathered.Öğe Enhanced fatigue behavior under internal pressure of CNT reinforced filament wound cracked pipes(ELSEVIER SCI LTD, 2017) Tasyurek, Mustafa; Tarakcioglu, NecmettinIn this study, the fatigue behavior of filament winding pipes was determined experimentally under internal pressure. Samples were produced by ultrasonication and the filament wound methods. In order to produce the CNTs/E Glass/Epoxy nanocomposite, CNTs and E-glass reinforcements and Bisphenol-A epoxy polymer matrix were used. Test specimens had antisymmetric six layers. All specimens had 55 winding angle. During all the experiments, the surface crack, fatigue crack growth rate and reinforcement condition of carbon nanotube were investigated. Two different rates of CNT (0.5% and 1%) were compared with the pure epoxy material. Effect of CNT on fatigue life was investigated experimentally. Cracks on the pipes for the fatigue tests had the aspect ratio of a/c = 0.2 and crack depth range between a/t = 0,25 and 0,50. Each test was repeated at least 3 times. Three different maximum stress levels were determined for the tests, which were 40%, 50% and 60% of the ultimate hoop stress. Fatigue life of nanocomposite pipes was found to increase with enhanced inter-laminar adhesion via CNTs. Stopping crack progression, bridging mechanism and mechanical interlocking between fibers of CNTs had been justified by SEM images. As a conclusion, material properties of GRP pipes were discussed by determining the effect of the reinforcement of carbon nanotubes. (c) 2017 Elsevier Ltd. All rights reserved.Öğe Enhancing Fatigue Life of Filament Winding Laminar and Curved Pipes Containing Carbon Nanotubes, and Their Fatigue Failure(SAGE PUBLICATIONS LTD, 2017) Tasyurek, Mustafa; Tarakcioglu, NecmettinIn this study, the fatigue life of glass fibre-epoxy matrix material produced by the filament winding composite pipes and matrix material reinforced with multi-walled carbon nanotubes (MWCNTs) nanocomposite filament winding tubes were studied experimentally under the influence of internal pressure. Glass-reinforced plastic (GRP) pipes which were reinforced with carbon nanotubes were tested in the conditions of an open-ended test. The winding angle of test specimens was +/- 55 degrees and they had six layers. During all the experiments, the fatigue life effect of reinforced carbon nanotubes was investigated. Unreinforced glass, as a reference material, was compared with reinforced plastic with the addition of nano-reinforced material using two different rates of 0.5% and 1%. Fatigue tests of specimens have been carried out in accordance with ASTM D-2992. Later on, the results obtained by determining the material properties with the reinforcement of carbon nanotubes GRP pipes were evaluated. As a result of this study, it has been found that MWCNTs reinforcement increases the fatigue life of the GRP tubes. Inter-laminar fracture strength was developed via the mechanical locking of MWCNTs. The critical MWCNTs usage value was between 0.5% and 1%.Öğe Fatigue behavior of surface cracked filament wound pipes with high tangential strength in corrosive environment(ELSEVIER SCI LTD, 2007) Avci, Ahmet; Sahin, Omer Sinan; Tarakcioglu, NecmettinThe aim of this study is to examine the corrosion fatigue behavior of filament wound composite pipes with a surface crack under alternating internal pressure. The filament wound pipes are composed of multi-layered E-glass/epoxy composites with a [+/- 75 degrees](3) lay-up. The surface notches were formed on the outer surface of the pipe along the pipe axis. Dilute (0.6 M) HCl acid was applied to the surface crack region by a corrosion cell mounted on the outer surface of the pipe. The results of an experimental investigation into the corrosion fatigue tests are conducted to observe the oil leakage failure and the crack propagation of the composite pipe subjected internal pressure loading with an open ended condition in which the pipe can be deformed freely in the axial direction. The internal pressure was generated by conventional hydraulic oil for fatigue loading. The fatigue tests are performed at 0.42 Hz frequency and a stress ratio of R = 0.05 in accordance with ASTM D-2992 standard. The oil leakage from the crack tip was observed after the crack propagation reached to the critical stress intensity level. The fatigue crack propagation behavior with the environment exposure was strongly dependent on the crack parameters such as crack-depth ratio and crack-aspect ratio. The micro structure of the fracture surface with the effect of environment and the fatigue loading were also observed. (c) 2006 Elsevier Ltd. All rights reserved.Öğe Fatigue crack growth of filament wound GRP pipes with a surface crack under cyclic internal pressure(SPRINGER, 2008) Samanci, Ahmet; Avci, Ahmet; Tarakcioglu, Necmettin; Sahin, Oemer SinanIn this study, fatigue damage behavior of (+/-75(3)) filament wound composite pipes with a surface crack under alternating internal pressure was investigated. The specimens were tested at room temperature and exposed to open ended fatigue tests in which the pipe can be deformed freely in the axial direction. The tests were carried out in accordance with the ASTMD-2992 standard. The alternating internal pressure was generated by conventional hydraulic oil. The low cycle tests were performed with 0.42 Hz frequency and R = 0.05 stress ratio. Glass reinforced polymer pipes (GRP) are made of E-glass/epoxy and have (+/-75(3)) configuration. Surface cracks were machined in the axial direction of the pipes which have depth-to-thickness ratios a/t = 0.25-0.38-0.50 and depth to length ratio of a/c = 0.2. Tests were performed at three different loads of 50%, 40%, and 30% of ultimate hoop stress strength of unnotched pipes. The failure behavior of GRP pipes during the test was observed and fatigue test results were presented by means of (S-N) Curves and delamination damage zone area-cycle (A-N) curves.Öğe Fracture toughness (Mode I) characterization of SiO2 nanoparticle filled basalt/epoxy filament wound composite ring with split-disk test method(ELSEVIER SCI LTD, 2017) Demirci, Mehmet Turan; Tarakcioglu, Necmettin; Avci, Ahmet; Akdemir, Ahmet; Demirci, IbrahimMatrix cracking which is the major initial form of damage in fiber reinforced polymer composites plays significant role in determining the fracture toughness. The fast crack propagation in polymer matrix causes to decrease the fracture toughness of fiber reinforced polymer (FRP) composite. In order to retard the fast crack propagation in polymer matrix and provide to increase of the fracture toughness of FRP composite, the polymer matrix of FRP composite is modified by filling the different kinds of nano particles. In such a way, the crack propagation leads to retard and dissipate the stress concentration affected to form the fiber cracks along of fibers in composite structure. In this study, basalt fiber was used as reinforcement material in +/-[55]6 filament wound ring composite for creating the alternative to carbon, kevlar and glass fibers, to contribute to the research studies and literature. SiO2 nanoparticles that provides to form the effects of fracture toughness mechanism based on the effect of retarding crack propagation were filled into epoxy matrix to increase the mechanical properties and fracture toughness of +/-[55]6 filament wound BFR/Epoxy ring composite. The split-disk tensile tests of single edge notched and un-notched +/- 155]6 filament wound BFR/Epoxy ring composite specimens were conducted to determine the mechanical properties and mode I fracture toughness. SiO2 nanoparticle addition into epoxy matrix of +/-[55]6 filament wound BFR/Epoxy ring composites has given the results of hoop tensile stress within the range of 27.7-30.3%. The fracture toughness of composite ring specimen was specified by ASTM E 399-12E3 by adapting to the directed mode I crack propagation and compared with each other. An effective increase in mode I fracture toughness of 43%-50% was obtained at 4 wt% addition level of SiO2 nanoparticles. The crack branching in epoxy matrix provided by SiO2 nanoparticle, matrix cracking, debonding, delamination and fiber breakage failures has been observed via microscope and SEM analysis. (C) 2017 Elsevier Ltd. All rights reserved.Öğe Fracture toughness of filament wound BFR and GFR arc shaped specimens with Charpy impact test method(ELSEVIER SCI LTD, 2014) Demirci, Mehmet Turan; Tarakcioglu, Necmettin; Avci, Ahmet; Erkendirci, Omer FarukThe aim of this study is an examination of Charpy impact behaviors of 6 layered basalt (BFR) and glass fiber reinforced (GFR) epoxy composite pipe at the degree of +/- 55 degrees filament winding angle with the arc-shaped specimen technique of different notch depth ratios (a/W). As a result of Charpy impact experiments, BFR composites were determined to have higher impact energy level and impact fracture toughness than GFR composites. The occurred average delamination areas in between layers were detected by an image processing method during the impact process. The delamination damage in GFR composites was observed to be more dominant damage than in BFR composites. It is understood that damage modes change when the notch depth ratio increases for composites. In BFR composites, the predominant damage mode was determined to be fiber breakage as a consequence of experiments and SEM analyses. (C) 2014 Elsevier Ltd. All rights reserved.Öğe Progressive fatigue failure behavior of glass/epoxy (+/- 75)(2) filament-wound pipes under pure internal pressure(ELSEVIER SCI LTD, 2009) Gemi, Lokman; Tarakcioglu, Necmettin; Akdemir, Ahmet; Sahin, Oeer SinanFatigue failure behaviors of filament-wound composite pipes under pure internal pressure were investigated. The filament-wound pipes are made of E-glass/epoxy and have four layers which have +/-75 degrees winding angle. The fatigue tests have been done in accordance with ASTM D-2992, which stipulate 0.42 Hz frequency and R = 0.05 stress ratio. Tests have been performed at different load levels from 30% to 70% of ultimate tangential strength of the pipe, the damage progression such as whitening, leakage and final failure have been observed, and S-N curves of these damages were obtained. (C) 2009 Elsevier Ltd. All rights reserved.
