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Öğe Prediction of the thermal conductivity of lightweight building materials utilizing backpropagation neural network method(Fırat Üniversitesi, 2015) Oktay, Hasan; Polat, Süleyman; Fidan, ŞehmusThe growing concern about energy consumption of heating and cooling of buildings has led to a demand for improved thermal performances of building materials. In this study, an experimental investigation is performed to predict the thermal insulation properties of wall and roof structures of which the mechanical properties are known, by using backpropagation artificial neural network (ANNs) method. The produced samples are cement based and have relatively high insulation properties for energy efficient buildings. In this regard, 102 new samples and their compositions are produced and their mechanical and thermal properties are tested in accordance with ASTM and EN standards. Then, comparisons have been made between the determined thermal conductivity of the newly produced structures, which are obtained from experimental method and ANN method that uses mechanical properties as input parameters. From the test results, since the percentage errors in the thermal conductivity values between experimental data and neural network prediction vary from - 1.09% to 6.4%, It can be concluded that the prediction of the artificial neural network has proceed in the correct manner.Öğe Experimental and articial neural network based studies on thermal conductivity of lightweight building materials(European Journal of Technique (EJT), 2017-04-01) Oktay, Hasan; Fidan, Şehmus; Sevim, Davut; Polat, SüleymanThe growing concern about energy consumption of heating and cooling of buildings has led to a demand for improved thermal performances of building materials. In this study, an experimental investigation is performed to predict the thermal insulation properties of wall structures of which the mechanical properties are known; by using Levenberg-Marquardt training algorithm based artificial neural network (ANNs) method for energy efficient buildings. The produced samples are cement based and have relatively high insulation properties for energy efficient buildings. In this regard, 102 new concrete samples and their compositions are produced and their mechanical and thermal properties are tested in accordance with ASTM and EN standards. Then, comparisons have been made between the experimental results and the ANN predicted results. It can be concluded that thermal performance of lightweight materials could be predicted with high accuracy using artificial neural network approach.Öğe Aramid fiber ve B4C parçacık ile takviye edilmiş Al7075 matrisli kompozitlerde haddelemenin ve yaşlandırmanın mekanik ve tribolojik özelliklere etkisi(Batman Üniversitesi, Fen Bilimleri Enstitüsü, 2021-06-28) Demir, Mehmet Emin; Çelik, Yahya HışmanAlüminyum alaşımlarının düşük üretim maliyetleri, iyi mekanik özellikleri ve yüksek korozyon dirençleri otomobil ve uzay endüstrisinde kullanılmalarını cazip kılmaktadır. Bu alaşımların farklı takviye parçacıkları ile güçlendirilmesi, ısıl işleme tabi tutulması veya haddelenmesi fiziksel, mekanik ve tribolojik özellikleri olumlu etkiler. Bu çalışmada, Al7075 alaşım matrisine 4 farklı takviye oranında (%4, %8, %10 ve %12) B4C parçacık ve aramid fiber ilave edilerek sıkıştırma döküm yöntemi ile malzemeler üretilmiştir. Üretilen malzemelerin mikroyapıları SEM ve optik mikroskop ile incelenmiş, faz oluşumları ise XRD ve EDX ile analiz edilmiştir. B4C/Al7075 kompozitlerin ve aramid/Al7075 alaşım malzemelerinin fiziksel (sertlik), mekanik (çekme, elastisite modulu, eğme) ve tribolojik özellikleri Al7075 alaşımıyla kıyaslanmıştır. Ayrıca en iyi mekanik özelliklerin elde edildiği B4C ve aramid takviyeli malzemelere ve Al7075 alaşımına, yaşlandırma ve haddeleme işlemi de uygulanarak bu işlemlerin sertlik, çekme ve eğme dayanımları ile tribolojik özelliklere etkisi araştırılmıştır. Numunelerin kırılma ve aşınma yüzeyleri SEM ile incelenmiştir. Takviye oranının etkisi incelendiğinde hem B4C hem de aramid takviyesi kullanılan malzemelerde en yüksek sertlik değerleri %12 takviye oranında görülmüştür. En yüksek çekme ve eğme mukavemeti ise B4C ve aramid takviyeli malzemeler için sırasıyla %10 ve %8 takviye oranından elde edilmiştir. %10 B4C/Al7075 kompozit malzemesinin çekme mukavemeti 249 MPa, eğme mukavemeti 494 MPa iken ve %8 aramid/Al7075 alaşım malzemesininki ise 278 MPa ve 454 MPa olarak belirlenmiştir. Sertlik değerinde olduğu gibi aşınma direncinde de en iyi değerler her iki takviye tipinde %12 oranından elde edilmiştir. B4C ve aramid takviyeleri Al7075 alaşımın aşınma direncini arttırmıştır. Yaşlandırmanın etkisi incelendiğinde, yaşlandırma süresine bağlı olarak malzemelerin belirlenen özelliklerinin oldukça geliştiği, ancak belirli bir yaşlandırma süresinden sonra kısmen düştüğü görülmüştür. Haddeleme işlemi de malzemelerin belirlenen özelliklerini geliştirmiştir, ancak bu etki yaşlandırma işlemindeki kadar yüksek olmamıştır.Öğe Experimental determination of the mechanical properties of composite materials produced with particle reinforced adhesives(European Journal of Technic, 2017-12) Adin, Hamit; Seven, Burhan; Çakar, Fahri; Yıldırım, Hayri; Ataş, İsaThe composite adhesives which are produced by adding particles into the structural adhesives used in aviation field as well as the latest developments in nanotechnology have given a new perspective to the design of adhesively bonded joints. In this study, the mechanical aspects of fibre glass composite materials produced with method hand lay-up by adding powder of composite material into adhesives were examined with an experimental manner under tensile load. Polyester was used as the structural adhesives; powder of fibre glass composite materials was used as additive materials at 1% or 2% by weight, and the samples of tensile were produced. The results of the experiment showed that tensile failure load was increased in the fibre glass composite material bonded with particle-reinforced adhesive. In addition, the study examined the force-displacement curves and found that the joints with nanoparticle-added adhesive had an increased displacement capacity.Öğe Characterization of hazelnut, pistachio, and apricot Kernel Shell particles and analysis of their composite properties(Taylor & Francis, 2021-05) Çelik, Yahya Hışman; Topkaya, Tolga; Kılıçkap, Erol; Başaran, Eyüp; Yalçın, RojinIn this study, hazelnut, pistachio, and apricot kernel shells were ground size of 0–300 µm, 300–600 µm, and 600–850 µm. The cellulose, ash, humidity, and metal contents of these powder particles were chemically analyzed and structural properties were characterized using X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectrometer (FT-IR) analysis. Their composites were fabricated by adding 0%, 10%, 20%, and 30% by weight of these powder particles to the polyester matrix material. The effect of chemical and structural properties of the powder particles on the physical, thermal, and mechanical properties of the composites was analyzed. The XRD analysis revealed that cellulose structure observed in powder particles. The peaks observed in their surface functional structures with FT-IR were mainly caused by cellulose and hemicellulose structures. These structures effected humidity and ash ratios. Nitrogen, carbon, hydrogen, and oxygen elements were seen in the structure. In addition, heavy metals such as Sn, Ca, K, Na, Mg, Fe, Ni, Mn, Cu, Zn, and Si were found. Powder particles added to the polyester material adversely affected the tensile strength of the matrix material. However, powder particles added to the matrix material at low rates had a positive effect on bending and compressive strength.Öğe Investigation of mechanical properties of lightweight concretes with different lightweight aggregates(Dicle University, 2019) Oktay, Hasan; Aydın, Hüseyin; Işık, Mehmet Zerrakki; Argunhan, ZekiEngineers have to know mechanical characteristics of lightweight concretes which are better than normal concretes. In this study, experimental investigations are performed for obtaining new concrete types to investigate the effect of lightweight aggregates on mechanical properties and to evaluate the relationships between the measured values of these properties. For this purpose, different types of concrete samples were prepared with a constant w/c, and normal aggregates replaced by lightweight aggregates such as pumice, expanded perlite and rubber aggregates at different volume fractions such as 10 %, 20 %, 30 %, 40 % and 50 % of the total aggregate volume. 102 samples were produced, and their mechanical characteristics were tested in accordance with ASTM and EN standards. Moreover, in order to evaluate possible correlations among the tested properties, a multivariate regression analysis was performed. Based on the experimental results, the expressions are presented to determine the relation between the mechanical properties of concrete samples. The results showed that both the compressive strengths and bulk densities of lightweight concrete samples decreased with increasing the (%) percentage of lightweight aggregate content. In addition, the regression analysis results show that if one of the mechanical properties of a structure is known, the other important properties can be calculated easily utilizing those expressions.
