IJET Vol. 3, Issue 2, June 2017
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International Journal of Engineering Technologies (IJET) Dergisi / International Journal of Engineering Technologies (IJET)
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Öğe International Journal of Engineering Technologies (IJET) Vol. 3, Issue 2, June 2017(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2017) Bayram, MustafaDear Colleagues, On behalf of the editorial board of International Journal of Engineering Technologies (IJET), I would like to share our happiness to publish the tenth issue of IJET. My special thanks are for members of editorial board, publication board, editorial team, referees, authors and other technical staff. Please find the tenth issue of International Journal of Engineering Technologies at http://ijet.gelisim.edu.tr or http://dergipark.gov.tr/ijet. We invite you to review the Table of Contents by visiting our web site and review articles and items of interest. IJET will continue to publish high level scientific research papers in the field of Engineering Technologies as an international peer-reviewed scientific and academic journal of Istanbul Gelisim University. Thanks for your continuing interest in our work, Professor Mustafa BAYRAM Istanbul Gelisim University mbayram@gelisim.edu.tr http://ijet.gelisim.edu.tr http://dergipark.gov.tr/ijet Printed ISSN: 2149-0104 e-ISSN: 2149-5262Öğe Prominence of Hadfield Steel in Mining and Minerals Industries: A Review(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2017-06-28) Okechukwu, Chijioke; Dahunsi, Olurotimi Akintunde; Oke, Peter Kayode; Oladele, Isiaka Oluwole; Dauda, MohammedHigh manganese austenitic steel, popularly called “Hadfield steel” has dominated and played significant role in wear applications, especially in the mines and minerals industries since its invention over a century ago. A review on the researches on this steel revealed that its prominence in these fields is mainly due to its good combination of impact and abrasion wear resistance arising from its high toughness and high hardness respectively. Its strain hardening ability under impact loading is evidenced by increase in hardness as the material work hardens; this lowers the amount of wear in service. The work hardening property of the steel has been linked to governing mechanisms such as dislocation, deformation twinning, and dynamic strain ageing; also, it is enhanced by increase in carbon, ageing temperature and reduction in manganese content. Carbide precipitation along the grain boundaries and within the grains is the major cause of embrittlement of the steel. These carbides together with voids and porosities during casting solidification, improper heat treatment, overheating during welding, use of unsorted scrap metal and wrong wear application have been identified as the causes of premature failure in service. Hardfacing method has been proposed as a means of substituting the steel in wear applications, as alternative wear materials such as white cast iron and austempered ductile iron lack the combination of impact and abrasion resistance being offered by the Hadfield steel.Öğe Optimum Insulation Thickness for the Exterior Walls of Buildings in Turkey Based on Different Materials, Energy Sources and Climate Regions(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2017-06-28) Aktemur, Cenker; Atikol, UğurThermal insulation improves the strength and longevity of buildings by reducing energy consumption, and as a related result, improved energy use. The selection of insulation material is governed by important parameters, including the average outdoor air temperature, the thermal conductivity of the buildings and the cost of the insulation material. Increases in the thickness of the insulation material will gradually decrease the energy consumption for heating; however, the insulation thickness has an optimum value that minimises the total investment cost, and determination of this optimum value is critical for economic analysis. In this paper, a life-cycle cost analysis is presented to show the optimum insulation thickness, energy savings over a lifetime of 15 years and payback periods for six different fuels and insulation materials for four cities in Turkey selected from climate regions identified by the Turkish Thermal Insulation Standard (TS 825). Muğla (1st region), Kocaeli (2nd region), Ankara (3rd region) and Ardahan (4th region) were selected for analysis of a sandwich-type wall constructed from the following six insulation materials: extruded polystyrene, expanded polystyrene, glass wool, rock wool, polyisocyanurate and polyurethane. The calculations were also made on the basis of six different fuels, such as motorin, natural gas, propane (LPG), electricity, coal (imported), and fuel-oil No. 4. As a consequence, results demonstated that the optimum insulation thickness vary between 2.8 cm and 45.1 cm, with energy savings between 16.4 ?/m2 and 479 ?/m2, and payback periods fluctuating between 0.078 and 0.860 years, depending on the city, the insulation material, and the cost of fuel.Öğe Conceptual Guideway Structural Design for MAGLEV High-Speed Ground Transportation System(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2017-06-28) Balkaya, Can; Hall, W.J.The conceptual guideway structural designs for MAGLEV (magnetic-levitation) high-speed ground transportation system are discussed by considering four different guideway designs of Bechtel, Magneplane, Grumman and Foster-Miller. The important aspects of the conceptual designs as well as some of the apparent shortcomings that will need attention in the design studies are emphasized. In this context the technical assessments and design observations may be considered for the guideway conceptual designs are given in this study.Öğe Engineering Material Selection for Automotive Exhaust Systems Using CES Software(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2017-06-28) Ikpe, Aniekan E.; Orhorhoro, Ejiroghene Kelly; Gobir, AbdulsamadThe aim of this report is focused onreviewing the automotive exhaust system with respect to its in-service conditionsand selection of suitablematerials for exhaust manifold, downpipe silencer/ muffler box and tail pipe in an exhaust system. In doing this, the functions of each component were discussed, highlighting how they function as part of a system and CES Edupack software was employed in the material selection process. Mass, cost, high temperature (>800oC for exhaust manifold and >400oC for downpipe silencer/ muffler box and tail pipe) and high corrosion resistance were used as criteria for the material selection. Variety of materials including Nickel-based superalloys, stainless steel, Nickel-chromium alloys were obtained in the search result for exhaust manifold. Similarly, low alloy steels, stainless steel, grey cast iron,Nickel-based superalloys, Nickel-chromium alloys were obtained in the search result for downpipe silencer/ muffler box and tail pipe. Nickel-based superalloys and Nickel-chromium alloys possess suitable properties for this application, but were not selected due to their high densities and high cost. Low allow steels were not selected because they tends to exhibits poor corrosion resistance when exposed to salt on the road surface and condensate from the exhaust system. Grey cast iron has low tensile strength and elongation and therefore not exhibit enough toughness required to withstand the severe working conditions.However, stainless steel (Ferritic stainless steel and Austenitic stainless steel) was selected due to its considerable price, low density, excellent corrosion resistant and acceptable strength at elevated temperatures.Öğe Lessons Learned from Collapse of Zumrut Building under Gravity Loads(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2017-06-28) Balkaya, CanThe 11-story reinforced concrete Zumrut Building in Konya, Turkey collapsed on February 2, 2004. Ninety-two people died. This study was conducted to determine the mechanism of the collapse and identify lessons learned to avoid future disasters. Using structural drawings, material samples, and soil information obtained from the site, reasons for the collapse were investigated. A three-dimensional (3-D) structural model and analyses were performed using ETABSV8.11, and various possible critical cases were studied. The step-wise nonlinear analysis used to obtain the collapse mechanisms was an example of forensic structural engineering and revealed that the progressive collapse of the building was torsional, caused by decrease in structural system’s capacity to redistribute gravity load after failure of a column. The lessons learned include the importance of project controls to reduce design and construction errors, ensure that construction and repairs are consistent with design intent, and changes are checked for safety and included in drawings. The importance of integrating architectural and structural systems to form 3-D continous structural frames to reduce the probability of progressive collapse is also discussed.Öğe Evaluation of Optimal Economic Life of Cemented Carbide Tool Turning AISI4340(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2017-11-13) Dahunsi, Olurotimi Akintunde; Awopetu, Olayinka Oladele; Ogedengbe, Tunde Isaac; Mohammed, Tiamiyu Ishola; Adamolekun, Taiwo MichealAs turning operation proceeds on a lathe machine, it is required that sufficiently good surface quality be achieved if all the affecting parameters, including tool geometry are held constant. In this paper, the effect of tool geometry variation due to wear in the case of C6 cemented carbide tool on AISI 4340, was studied. Using surface roughness as yardstick for estimating the point beyond which the maximum economic utilization derivable from the tool is hampered, it was realized that each insert should be replaced after ten minutes of turning operation to retain their optimum usefulness. The tool wear parameters were found to be in linear relationship with the cutting time, while the average surface roughness was modelled nonlinearly using an exponential function. A fourth degree polynomial approximated the trend for the cutting force. Sharp deflections were observed on the surface roughness and cutting force graphs after the tenth minute. Generally for the entire cutting time, the measured cutting force increased by about 33% while the flank wear width and crater wear width increased by 170% and 56% respectively. Surface roughness also increased by about 130%.
