60 research outputs found
Analysis of under-constrained and unstable structures by the method TPO/MA
No full textBekdaş, Gebrail/0000-0002-7327-9810; Toklu, Y. Cengiz/0000-0002-1550-1911;Under-constrained and unstable structures are those which are kinematically unstable. They may show large displacements even under very small forces contrarily to well-constrained stable structures. Under-constrained structures manifest themselves with insufficient boundary conditions. On the other hand, structures with missing members may become kinematically unstable under certain loadings. A common property of these structures is that the rank of their stiffness matrix, used in their analysis by classical methods, comes out to be zero, thus making impossible their analysis by these methods. Fortunately, application of the method Total Potential Optimization using Metaheuristic Algorithms (TPO/MA) makes the analysis of these structures very simple, with no extra difficulty as compared to the analysis of well-constrained stable structures. Examples shown in this study are demonstrating this fact
SPACE RESEARCH AND EXTRATERRESTRIAL CONSTRUCTION INDUSTRY
No full textToklu, Y. Cengiz/0000-0002-1550-1911Advance of civilization has been realized through the ages by exploration of unknown parts of the Earth and by exploiting new resources thus acquired. There are currently practically no new areas on this planet to be explored and exploited. This is achieved by the completion of the period called globalization. As a natural continuation of this process, humans will now explore and exploit new areas beyond Earth, i.e. in space. Moon has already been explored partly, it awaits a complete exploration and colonization. The next step will be Mars and beyond. Habitation on these new space bodies will firstly necessitate construction of outposts on these bodies. Thus construction on the Moon, Mars, and other space bodies can be considered to be an important component of space research. In the present article, an overview of space research is presented together with the innovations awaited in space construction industry and the importance of feedback of these studies to construction industry in general.Conference Proceedings Citation Index - Scienc
Minimization of vertical deflection of an optimum I-beam by Jaya algorithm
No full textToklu, Y. Cengiz/0000-0002-1550-1911; Bekdaş, Gebrail/0000-0002-7327-9810;In civil engineering, optimization is an important issue in minimization of structural responses or production costs. In optimization methodologies, metaheuristic methods are effective in finding precise results. In this study, a new developed metaheuristic algorithm called Jaya Algorithm (JA) is applied to a basic structural optimization problem. In this problem, the dimensions of an I-beam are optimized for the minimization of the vertical deflection. The result of the numerical example was compared with the results existing in the literature. It is seen that the JA method is more favorable than the others as far as the computational effort is concerned. Also, the effect of population number was tested for the I-beam problem
Large deflection analysis of elastic cantilevers
Get PDFAnadolu Üniversitesi ve Bilecik Şeyh Edebali Üniversitesi tarafından ortak yürütülen program.Bu çalışma kapsamında elastik konsol bir kirişin statik analizi Euler-Bernoulli eşitlikleri kullanılarak yinelemeli bir yöntemle yapılmıştır. Bu amaçla kiriş eşit uzunlukta parçalara bölünmüş ve ötelenmelerin hesabında, bu parçalar üzerindeki dönmelerin doğrusal değiştiği kabulü yapılmıştır. Başlangıçta kirişe verilen yükün kirişte oluşturduğu şekil değiştirmeler belirlenmiş, şekil değiştirmiş kirişe tekrar aynı yükler etki ettirilerek şekil değiştirmeler doğrusal olmayan şekilde tekrar belirlenmiştir. Bu işlem şekil değiştirme sonuçları yeteri kadar birbirine yaklaştığında bitirilerek kirişin gerçek şekil değiştirmesi bulunmuştur. Yineleme işlemi Ms Excel ve MATLAB programlarında yapılmış, MATLAB GUI ile de kullanıcı arayüzü oluşturulmuştur. Ayrıca şekil değiştirmeler enerji en küçüklemesi yöntemi ile bulunarak sonuçlar birbirleri ile ve klasik yöntemlerden bulunan sonuçlar ile karşılaştırılmıştır.In the context of this study, structural analysis of an elastic cantilever has been conducted using an iterative method based on Euler-Bernouilli equations. For this purpose, the beam has been considered to be divided into elements of equal length and the rotational angles have been assumed to be linearly changing over these elements in computing the elastic curve. At the beginning, the deformations caused by the loads acting on the structure is determined, and then by application of the loads on the deformed system, the new deflections are re-calculated. This procedure is repeated until stabilization of deflections and rotations. The iterative process has been conducted using MS Excel and also by programming with MATLAB. A user friendly interface is also produced by MATLAB GUI. The deflections are also computed with total potential minimization technique. Results are compared with each other and with computations based on classical methods
Improving the mechanical properties of hydrated lime and cement mortars using powdered Bayburt stones and zeolite
No full textFen Bilimleri Enstitüsü, İnşaat Mühendisliği Ana Bilim DalıBu tez çalışması yığma yapılarda kullanılan kireç ve çimento harçlarının daha sağlıklı ve doğru şekilde kullanılabilmesi için kireç ve çimento harçlarının taze ve sertleşmiş özelliklerinin zeolit ve toz haline getirilmiş Bayburt taşlarıyla manipüle edilebilirliği üzerine yapılmış bir çalışmadır. Çalışma kapsamında yığma yapılardaki kireç ve çimento harçlarından kaynaklanan bazı hasarlar ve yapım anında veya sonrasında çimento ve kireç harçlarının bazı dezavantajları ortaya konduktan sonra zeolit ve toz haline getirilmiş Bayburt taşlarıyla harçları manipüle ederek ortaya konan sorunların çözümü aranmıştır. Çalışmada Manisa/Gördes'ten elde edilmiş zeolit ve Bayburt ilinden temin edilen Bayburt Sarı, Bayburt Beyaz, Bayburt Yeşil taşları kullanılmıştır. Bayburt taşlarının puzolanik özellik gösterebilmesi ve zeolit ürünü ile kıyaslanabilmesi için benzer granülometri eğrileri elde edilmiştir. Deney için karışım tasarımı standartlara bağlı kalarak oluşturulmuş ve her ikame malzemesi için %2,5, 5, %10, %20, %30, %40 ve %50 oranlarında katkının yapılması uygun bulunmuştur. Her yüzdelik katkı oranı için 6 küp ve üç kiriş numune dökülmüştür. Çimento harçları için 14. gün, 21. gün ve 28. günlerde kireç harçları için 28. gün, 56. gün ve 91. günlerde basınç ve eğilme dayanımı testi uygulanmıştır. Diğer deneyler harçlar taze halde iken uygulanmıştır. Elde edinilen sonuçlar incelendiğinde kireç ve çimento harçları özelliklerinin zeolit ve toz haline getirilmiş Bayburt taşları ile manipüle edilebilirliği ortaya çıkmıştır ve tezin başında ortaya konan problemlere ışık tutmuştur. Sonuçlara göre zeolite ve Bayburt taşları katkısı ile kirecin harcının basınç dayanımının %60 oranlarına kadar arttığı, su iletme kapasitesinin 4 kat arttığı, su iletme süresinin ise 4 kat azaldığı, priz süresinin %40'lara varan oranlarda iyileştirilebildiği ve kıvamın manipüle edilebilirliği görülmüştür. Zeolite ve Bayburt taşları katkıları ile çimento harcının kontrol numuneye göre basınç dayanımının %65'ler oranında azaldığı, prizlenme süresi ve kıvam değerlerinin ise zeolite ve Bayburt taşları ile manipüle edilebilirliği görülmüştür.This thesis is focusing on the manipulation of fresh and hardened state properties of hydrated lime and cement mortars using powdered Bayburt stones and zeolite for their more compatible and appropriate use in masonry construction. Damages that occur during and after the constructions using cement and hydrated lime mortars are defined and the disadvantages of the using these mortars are noted to investigate whether the required properties of these mortars could be manipulated to remedy the problematic applications of these mortars in masonry construction. In this study, zeolite that obtained from Manisa/ Gördes and Bayburt Yellow, Bayburt White, Bayburt Green stones obtained from Bayburt are used. In order to increase the pozzolanic properties and to be comparable to zeolite, similar particle size distribution for Bayburt stones are obtained to zeolite. Mix design calculations for the experiments were carried out based on the standards the % of 2,5, 5, 10, 20, 30, 40 and 50 replacement levels for both binders found to be suitable. For each replacement level, 6 cube and 3 beam samples were cast. Compressive and flexural strength measurements were done at 14th, 21th and 28th days for cement and at 28th, 56th and 91th days for hydrated lime mortars. All the other experiments were carried out at the fresh state of the mortars. When the results are studied, it was found out that the properties of hydrated lime and cement mortars can be manipulated using powdered Bayburt stones and zeolite and have elucidated the problems stated at the beginning of this thesis. According to the experimental results, the replacement levels of both zeolite and Bayburt stones resulted in %60 increase in strength, 4 times higher increase in transfer sorptivity and therefore 4 times lower decrease in time to dewatering, %40 improvement in setting time and manipulation of consistency is observed. Compressive strength of cement mortars using zeolite and Bayburt stones is decreased by %65 compared to the control cement mortar and was also observed that setting time and consistency could be manipulated when zeolite and Bayburt stones are used
Social, historical and international aspects of space research
No full textMen has completed the phase “globalization” on
Earth by conquering almost all parts of the globe, by using
almost all resources offered by this planet, in a collaborative way
involving all habitants. Now it is time to start founding
establishments out of this world, i.e. “spatialization” to mean
“becoming citizens of space”. In this study we first discuss the
mechanism of globalization and passage to spatialization. We
discuss also the benefits of this new phase to habitants of Earth.
Examples are given to show how space research helps to increase
the level of comfort of human beings on Earth. It is also discussed
that although space research is an expensive activity, it may be
broken down to smaller pieces to enable all countries and private
companies to enter into this race. Such a breakdown will help
more even distribution of wealth among nations and peoples on
Earth.Bu yayın ''IEEE; AIAA; URSI; AESS; GRSS; EARSeL; ISPRS; Turkish Air Force Acad; Istanbul Tech Univ; Bogazici Univ; Middle E Tech Univ; Yildiz Tech Univ; Roketsan; Havelsan; Turksat; Aselsan; TAI; Tusas Engine Ind Inc; Petlas; ALP Havacilik; Mitsubishi Elect; Space & Defence Technologies; ThalesAlenia Space; Savunma Havacilik; MSI'' tarafından desteklenmişti
Otomatik Yapı Üretim Teknolojisinde Kullanılabilecek Malzemelerin Belirlenmesi
Get PDFOtomatik yapı üretim teknolojisi robotik temellidir ve katmanlı üretim teknolojisini kullanarak bilgisayar kontrolü altında büyük ölçekli nesneleri kalıp kullanmadan 3 boyutlu beton yazıcı cihazı aracılığıyla inşa edebilir. Bu çalışmanın amacı otomatik yapı üretim teknolojisinde, 3 boyutlu beton yazıcı cihazında kullanılabilecek uygun kıvamdaki harçları, düşük maliyetli en uygun malzemelerle oluşturabilmektir. Sonuç olarak düşük maliyetli malzemeler araştırılarak bu malzemeler kum, diatomit, çimento, öğütülmüş yüksek fırın cürufu, selüloz ve polipropilen lif olarak belirlenmiştir. Bu malzemeler kullanılarak 3 boyutlu beton yazıcı cihazında kullanılabilecek uygun kıvamda 7 adet deneme karışımı tespit edilmiştir. Bu karışımlar ile yoğunluk tayini, yayılma, basınç ve eğilme dayanımı deneyleri yapılmış, çökme deneyi ile kullanım süreleri belirlenmiş ve karışım oranları verilmiştir. Bu 7 adet deneme karışımlarından birinci olarak Deneme 2, ikinci olarak Deneme 3 ve üçüncü olarak Deneme 7’nin, 3 boyutlu beton yazıcı cihazında kullanımının diğer karışımlara göre daha uygun olduğu belirlenmiştir
Lunar soils, simulants and lunar construction materials: An overview
Get PDFOne of the hot subjects in space civil engineering is the research for establishing outposts on space bodies, starting with the Moon. This wide research topic mainly covers learning about ground conditions and soils of these extraterrestrial bodies, looking for means of using the soil in producing construction materials, designing structures appropriate for local conditions, and finally choosing construction techniques to be applied using mainly these materials. In this paper, as the title indicates, an overview is presented on three aspects of using local materials in lunar construction activities: nature of in-situ soils obtained with lunar missions, the variety of lunar soil simulants produced on Earth, and their use in producing lunar construction materials. (C) 2022 COSPAR. Published by Elsevier B.V. All rights reserved.Beykent University Scientific Research Projects Coordination Unit [2018-19-BAP-01]This research has been supported by Beykent University Scientific Research Projects Coordination Unit. Project Number: 2018-19-BAP-01, 2021
Analysis of Tensegric Structures by Total Potential Optimization Using Metaheuristic Algorithms
No full textTensile integrity (tensegrity, tensegric) structures are suggested for possible use in architectural works, bridges, covering large areas, and especially for habitats in outer space and on space bodies because of their minimal need for structural materials and ease of transfer and mounting. Structurally, their behavior is nonlinear and thus their analysis necessitates special care with recourse to special techniques. This study shows that their structural analysis can successfully be performed by a method called total potential optimization using metaheuristic algorithms (TPO/MA) with no special precautions in a very general way. In the applications, which are conducted using software prepared for analyzing all types of nonlinear trusses and trusslike structures, the load-displacement behaviors of tensegric structures are investigated to include also the effect of prestressing level on cables. Genetic algorithms are used in this study as the metaheuristic technique for solving the optimization part of the problem
Lunar Soil Simulants- An Assessment
Get PDF9th International Conference on Recent Advances in Space Technologies (RAST) -- JUN 11-14, 2019 -- Istanbul, TURKEYIn this study an assessment is done about lunar soil simulants. It is found that until now more than 40 simulants are produced in 9 countries. This procedure is a still ongoing one, after its start in the year 1990. The list of the simulants produced given in the paper is the most comprehensive one and it includes not only all of the types given in previous surveys, but also presents information on the most recent simulants that were produced within the last decade. The properties of the simulants are explained briefly. Possible uses of lunar soils in lunar constructions are also explained. The fact that all countries, even those which are not considered as developed ones, can take place in this field of research is also emphasized
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