Hacettepe Ankara Sanayi Odası 1. OSB Meslek Yüksekokuluhttp://hdl.handle.net/11655/1122020-12-03T06:55:54Z2020-12-03T06:55:54ZDetermination of The Modulus of Elasticity of Wooden Construction Elements Reinforced with Fiberglass Wire Mesh And Aluminum Wire MeshAbdullah, TogayDöngel, NihatSöğütlü, CevdetErgin, EmreÜzel, MuratGüneş, Serkanhttp://hdl.handle.net/11655/220752020-09-14T12:10:08Z2017-01-01T00:00:00ZDetermination of The Modulus of Elasticity of Wooden Construction Elements Reinforced with Fiberglass Wire Mesh And Aluminum Wire Mesh
Abdullah, Togay; Döngel, Nihat; Söğütlü, Cevdet; Ergin, Emre; Üzel, Murat; Güneş, Serkan
Laminated composite wooden construction elements were produced with 7 layers of Scots pine (Pinus sylvestris L.). Fiberglass wire mesh and aluminum wire mesh, which were used as reinforcement materials, were pressed with polyvinyl acetate (PVAc) and polyurethane-type adhesives between each Scots pine layer. The highest bonding strength values were obtained from laminated control specimens produced with polyurethane adhesive without using support materials (4.98 N/mm(2)) and laminated control specimens made with polyurethane adhesive without using support materials (4.39 N/mm(2)), respectively. The modulus of elasticity in bending perpendicular to the glue line values of all the specimens except the laminated control specimens produced with polyurethane adhesive without using support materials (14800 N/mm(2)) were lower than solid wood (6720 N/mm(2)). In contrast, in the experiments for the modulus of elasticity parallel to the glue line, the variables (adhesive, intermediary layer materials) used for all experiments and specimens were effective factors. Although the modulus of elasticity in bending parallel to the glue line values of all samples were higher than solid wood (6720 N/mm(2)), the maximum value was obtained in the laminated control specimens produced with polyurethane adhesive without using support materials (17800 N/mm(2)).
2017-01-01T00:00:00ZEffects Of Control Factors On Operating Temperatures Of A Mechanical Heat Pump In Waste Heat Recovery: Evaluation Using The Taguchi MethodMotorcu, Ali RızaÇoşkun, SalihKarabulut, Şenerhttp://hdl.handle.net/11655/220462020-09-14T13:31:38Z2018-01-01T00:00:00ZEffects Of Control Factors On Operating Temperatures Of A Mechanical Heat Pump In Waste Heat Recovery: Evaluation Using The Taguchi Method
Motorcu, Ali Rıza; Çoşkun, Salih; Karabulut, Şener
In the present study, the operating temperatures of the mechanical heat pump in waste heat recovery were investigated to elucidate the effect of control parameters such as compressor speed, wastewater temperature and mass flow rate. The experimental trials were performed using the Taguchi L27 full factorial orthogonal array, and the results were optimized for compressor suction gas temperature, compressor discharge gas temperature, temperature difference of water entering and leaving the evaporator, temperature difference of water entering and leaving the condenser, evaporation temperature, and condensation temperature. Analysis of variance was conducted to determine the effect of the control factors on the operating temperatures of mechanical heat pump. The analysis results show that the wastewater temperature was the most significant factor on compressor suction gas temperature and discharge gas temperature. The compressor speed has shown a meaningful effect on the temperature difference of water entering and leaving from condenser. The nominal levels of control factors and the optimal temperatures were specified for the studied experimental parameters. Prediction models were developed for the operating temperatures through the Taguchi method and the operating temperatures were predicted with a mean squared error less than 12%.
2018-01-01T00:00:00ZEffect of Microstructure on Fatigue Strength of Intercritically Austenitized and Austempered Ductile Irons With Dual Matrix StructuresOvalı, İsmailKılıçlı, VolkanErdoğan, Mehmethttp://hdl.handle.net/11655/220422020-09-14T13:30:27Z2013-01-01T00:00:00ZEffect of Microstructure on Fatigue Strength of Intercritically Austenitized and Austempered Ductile Irons With Dual Matrix Structures
Ovalı, İsmail; Kılıçlı, Volkan; Erdoğan, Mehmet
In the present study the fatigue strength of austempered ductile irons with dual matrix structures (ADI with DMS) has been studied for an unalloyed ductile cast iron. For this purpose, specimens were intercritically austenitized (partially austenitized) in two phase region (alpha + gamma) at various temperatures (810 degrees C, 820 degrees C and 830 degrees C) for 20 minutes and then quenched into salt bath held at austempering temperature of 315 degrees C and 375 degrees C for 120 minutes and then air cooled to room temperature to obtain various ausferrite volume fractions and their morphologies. Conventionally austempered specimens (austempered from 900 degrees C) with fully ausferritic matrix and unalloyed as cast specimens having ferrit + pearlite structures were also tested for a comparison. Rotating bending fatigue test were carried out an the experimental results showed that, in ADI with DMS, volume fraction of ausferrite and continuity of ausferritic structure along intercellular boundaries play important role in determining fatigue strength. The fatigue strength of these specimens increases with increasing ausferrite volume fraction. The fatigue strength was correlated with the ausferrite volume fraction and high carbon austenite and its carbon content. Conventionally austempered specimens exhibited much greater fatigue strength than ADI with DMS specimens.
2013-01-01T00:00:00ZExperimental Investigation of B4C Particulate Reinforced
Aluminium 6061 Based Composite Material in Wire-Cut EDMKarabulut, Ş.Gökmen, U.Karakoç, H.Hakan, Ö. K.Çitak, R.http://hdl.handle.net/11655/219072020-09-14T13:39:37Z2016-01-01T00:00:00ZExperimental Investigation of B4C Particulate Reinforced
Aluminium 6061 Based Composite Material in Wire-Cut EDM
Karabulut, Ş.; Gökmen, U.; Karakoç, H.; Hakan, Ö. K.; Çitak, R.
In the present paper, the influences of cutting parameters on surface roughness in wire electric-discharge machining of (WEDM) process of particle-reinforced aluminium AA6061 alloy composite are investigated. The composites are produced using 15% wt. B4C fraction using powder metallurgy. Experimental trials are performed based on Taguchi L18 (21×32) with a mixed orthogonal array, and the WEDM cutting parameters are optimized for the best surface quality. The investigation results are evaluated by response surface plots and main effect graphs. The machined surface of the metal matrix composite is investigated using scanning electron microscopy (SEM) micrographs. The effect of WEDM machining variables are determined using analysis of variance (ANOVA). The analysis result shows that the most significant cutting parameter is peak current for surface roughness. The SEM and optical micrographs indicate that the reinforced B4C particles are homogeneously distributed in the matrix structure. Mathematical models are also generated using regression analysis for the surface roughness. Confirmation tests are carried out to determine the prediction performance of the mathematical models, and the surface roughness is predicted with an acceptable mean squared error.
2016-01-01T00:00:00Z