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Öğe The Effect of Hydrothermal Aging on the Low-Velocity Impact Behavior of Multi-Walled Carbon Nanotubes Reinforced Carbon Fiber/Epoxy Composite Pipes(Springer, 2021) Kara, Memduh; Ak, Safa; Uyaner, Mesut; Gunoz, Alper; Kepir, YusufChemical transmission lines, petroleum and natural gas lines, pressure vessels, and pipes used in thermal facilities are expected to maintain their mechanical properties for many years without being damaged and not to be corroded in working conditions. The composite materials are the right candidate for these harsh conditions due to their superior properties. Reinforcement of nanoadditives to composite materials improves both the mechanical properties and the resistance to environmental conditions, thereby increasing the lifetime. In this study, multi-walled carbon nanotube (MWCNT) reinforced [+/- 55 degrees] carbon fiber/epoxy composite pipes produced with filament wound method were used. It was hydrothermally aged in 80 degrees C distilled water for 1, 2, 3 weeks in order to examine the effect of environmental conditions. In order to investigate its resistance against loads that may occur in working conditions, ring tensile tests (ASTM D 2290-16 procedure A), and low-velocity impact tests at 5, 10, 15 J, energy levels were carried out. The effect of hydrothermal aging on neat and MWCNT added epoxy composite had been examined by considering the aging period. Consequently, the impact resistance of neat and MWCNT added samples decreased with the aging process. Besides, tangential tensile strength loss was 17% in MWCNT reinforced sample and 13% in the neat sample.Öğe Karbon nanotüp ve bor nitrür nano partikülleri ilaveli karbon fiber-epoksi kompozit borularının mekanik özelliklerine hidrotermal yaşlandırmanın etkisi(Necmettin Erbakan Üniversitesi Fen Bilimleri Enstitüsü, 2019) Ak, Safa; Kara, MemduhFilaman sarma tekniği ile üretilmiş kompozit borular diğer borulara göre düşük ağırlıklı yüksek mukavemetli, kimyasal maddelerin oluşturacağı korozyona, olumsuz hava koşullarına ve ultraviyole ışınlara karşı dirençli ve uzun ömürlüdürler. Tüm bu üstün mekanik, kimyasal ve termal özellikleri sayesinde metal ve diğer malzemelerin yerini almakta olan filaman sarma tekniği ile üretilmiş kompozit boruların petrol-doğalgaz iletim hatları, kimyasal akışkanların iletim hatları, şehir şebeke su tesisatları, termal tesisler ve basınçlı kaplar gibi yaygın kullanım alanları mevcuttur. Operasyon alanın koşul ve şartları kompozit malzemelerin çalışma ömrü ve performansı üzerinde çok etkilidir. Bu sebepte çalışmada daha önceden hazırlanmış [±55o]4 sarma açısına ve 8 katmana sahip Karbon fiber/epoksi saf, Bor Nitrür Nanopartikül (BNNP), Çok Cidarlı Karbon Nanotüp (ÇCKNT) ve hem BNNP hem de ÇCKNT katkılı hibrit borular 1, 2 ve 3 haftalık sürelerde saf su içerisinde 80 oC sıcaklık etkisinde hidrotermal yaşlanmaya maruz bırakılmıştır. Her boru grubunda yaşlandırılmayan kontrol grubu bulunmaktadır. Mekanik özelliklerin belirlenmesi aşamasında ise numunelere ASTM D 2290-16 prosedür A standartlarında halka çekme deneyi ve 5j, 10j, 15j, enerji seviyelerinde düşük hızlı darbe deneyi uygulanmıştır. Deney sonuçlarının grafikleri çizilerek değerlendirilmiştir. Hidrotermal yaşlandırmanın saf epoksi kompozit ve farklı nanopartikül ilaveli epoksi kompozit malzemeler üzerindeki etkisi yaşlandırma süreleri göz önünde bulundurularak incelenmiştir.Öğe Mechanical Properties and Damage Behaviours of Polyurethane Composites Reinforced With BNNP and MWCNT Hybrid Nanoparticles(Sage Publications Ltd, 2023) Bahtiyar, Guelay; Ekrem, Mursel; Unal, Bayram; Ak, SafaIn recent years, with increasing engineering applications, structural adhesives have played an increasingly important role in joining both metallic and non-metallic components. Polyurethane is frequently used in the adhesive industry due to its morphological structure, versatile material, and excellent matrix material. In addition, by doping polyurethane with single/multi-walled carbon nanotubes and boron nitride nanoplates materials, the mechanical properties of the polyurethane adhesive can be further increased. This study aimed to increase the mechanical properties of PU (thermoset polyurethane), which is frequently used in adhesively bonded joints by addition of MWCNT (multi-walled carbon nanotubes), BNNP (boron nitride nanoplates). For this purpose, nanoparticles synergistic interaction was investigated by adding a mass of 0.25%, 0.35%, and 0.45% MWCNT into PU, which was reinforced by 0.5% BNNP before. Samples mechanical properties were determined by tensile test according to ASTM D638-10 standard, flexure test according to ASTM D790-02 standard, and Shore D test according to ASTM D2240 standard. All sample test results were graphed, and each graph was compared. Also, broken surfaces were analyzed by scanning electron microscopy (SEM) to examine the damage mechanism of nanoparticles.