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Harmoni arama yöntemi kullanılarak geometrik yönden doğrusal olmayan tek katmanlı yapraksı kubbelerin optimum topoloji boyutlandırması.
No full textHarmony search method based optimum topology design algorithm is presented for single layer lamella domes. The harmony search method is a numerical optimization technique developed recently that imitates the musical performance process which takes place when a musician searches for a better state of harmony. Jazz improvisation seeks to find musically pleasing harmony similar to the optimum design process which seeks to find the optimum solution. The optimum design algorithm developed imposes the behavioral and performance constraints in accordance with LRFD-AISC. The optimum number of rings, the height of the crown and the tubular cross-sectional designations for dome members are treated as design variables. The member grouping is allowed so that the same section can be adopted for each group. The design algorithm developed has a routine that build the data for the geometry of the dome automatically that covers the numbering of joints, and member incidences, and the computation of the coordinates of joints. Due to the slenderness and the presence of imperfections in dome structures it is necessary to consider the geometric nonlinearity in the prediction of their response under the external loading. Design examples are considered to demonstrate the efficiency of the algorithm presented.M.S. - Master of Scienc
Izgara sistemlerinin harmoni arama yöntemi kullanılarak optimum boyutlandırılması.
No full textHarmony search method based optimum design algorithm is presented for the grillage systems. This numerical optimization technique imitates the musical performance process that takes place when a musician searches for a better state of harmony. For instance, jazz improvisation seeks to find musically pleasing harmony similar to the optimum design process which seeks to find the optimum solution. The design algorithm considers the displacement and strength constraints which are implemented from LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Construction). It selects the appropriate W (Wide Flange)-sections for the transverse and longitudinal beams of the grillage system among 272 discrete W-section designations given in LRFD-AISC so that the design limitations described in LRFD are satisfied and the weight of the system is confined to be minimal. Number of design examples is considered to demonstrate the efficiency of the algorithm presented.M.S. - Master of Scienc
Betonarme düzlem çerçevelerin armoni tarama yöntemi ile optimum tasarımı.
No full textIn this thesis, the optimum design algorithm is presented for reinforced concrete special moment frames. The objective function is considered as the total cost of reinforced concrete frame which includes the cost of concrete, formwork and reinforcing steel bars. The cost of any component is inclusive of material, fabrication and labor. The design variables in beams are selected as the width and the depth of beams in each span, the diameter and the number of longitudinal reinforcement bars along the span and supports. In columns the width and the depth of the column section, the number and the diameter of bars in x and y directions are selected as design variables. The column section database is prepared which includes the width and height of column section, the diameter and the number of reinforcing bars in the column section is constructed. This database is used by the design algorithm to select appropriate sections for the columns of the frame under consideration. The design constraints are implemented from ACI 318-05 which covers the flexural and shear strength, serviceability, the minimum and maximum steel percentage for flexural and shear reinforcement, the spacing requirements for the reinforcing bars and the upper and lower bound requirements for the concrete sections. The optimum design problem formulated according to ACI 318-05 provisions with the design variables mentioned above turns out to be a combinatorial optimization problem. The solution of the design problem is obtained by using the harmony search algorithm (HS) which is one of the recent additions to meta-heuristic optimization techniques which are widely used in obtaining the solution of combinatorial optimization problems. The HS algorithm is quite simple and has few parameters to initialize and consists of simple steps which make it easy to implement. Number of design examples is presented to demonstrate the efficiency and robustness of the optimum design algorithm developed.Ph.D. - Doctoral Progra
Soğuk şekillendirilmiş ince cidarlı çelik kesitlerden yapılan az katlı çelik çerçevelerin optimum tasarımı.
No full textThin-walled section is the one which is made of thin plates. The thickness of thin plates is quite small compared to other cross-sectional dimensions as well as overall length of the member or substructure. Elements made of thin-walled sections are used extensively in steel and concrete bridges, ships, aircraft, mining head frames, and gantry cranes. One common feature of these members made of thin-walled sections is that they are very light compared with alternative sections and, therefore, they are used extensively in long-span structures where the economy is of prime consideration. Thin-walled sections may have a closed or open form. The open thin-walled sections possess small torsional rigidity and they undergo warping deformation when subjected to torsional moments. The warping deformation in turn generates significant normal stresses that are to be considered in the design of such sections. In this thesis, at first an optimum design algorithm is developed for thin-walled beams with open sections when they are subjected to bi-axial bending and torsion. The dimensions of thin plates joined together to constitute the thin-walled section including their thickness are taken as design variables. The displacement, stress and local buckling constraints are considered in the formulation of the design problem. Vlasov’s theory is used to calculate the normal and shear stresses that occur due to warping. Besides, this study also aims to produce optimum design of cold-formed thin-walled open sections and optimum design of steel frame made of these kinds of sections given in AISI-LRFD. For this purpose, a different optimum design algorithm is developed which imposes the behavioral and performance constraints in accordance with AISI-LRFD. Moreover, due to the slenderness and the presence of imperfections in cold-formed thin-walled open sections and steel frames built up with these sections, it is necessary to take cognizance of the geometric nonlinearity into account in the prediction of their response under the external loading in both cases. Afterwards, the optimum design problems obtained turn out to be mixed integer and discrete programming problem. Artificial bee colony algorithm is used to obtain their solution. This technique is a recent numerical optimization technique which mimics the intelligent behavior of honey bee swarm. The recent studies with the artificial bee colony method have shown its effectiveness and robustness in finding the optimum solution of combinatorial optimization problems. Number of design examples is included to demonstrate the competence of the optimum design algorithms developed.Ph.D. - Doctoral Progra
Dzensiz üç boyutlu çelik çerçevelerin karınca koloni optimizasyonu ve harmoni arama yöntemleri ile optimum boyutlandırılması.
No full textSteel space frames having irregular shapes when subjected to lateral loads caused by wind or earthquakes undergo twisting as a result of their unsymmetrical topology. As a result, torsional moment comes out which is required to be resisted by the three dimensional frame system. The members of such frame are generally made out of steel I sections which are thin walled open sections. The simple beam theory is not adequate to predict behavior of such thin-walled sections under torsional moments due to the fact that the large warping deformations occur in the cross section of the member. Therefore, it is necessary to consider the effect of warping in the design of the steel space frames having members of thin walled steel sections is significant. In this study the optimum design problem of steel space frames is formulated according to the provisions of LRFD-AISC (Load and Resistance factor design of American Institute of Steel Construction) in which the effect of warping is also taken into account. Ant colony optimization and harmony search techniques two of the recent methods in stochastic search techniques are used to obtain the solution of the design problem. Number of space frame examples is designed by the algorithms developed in order to demonstrate the effect of warping in the optimum design.Ph.D. - Doctoral Progra
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Suni Arı Kolonisi Yöntemi Kullanılarak Soğuk Şekillendirilmiş İnce Cidarlı Çelik Kesitlerden Yapılan Az Katlı Çelik Çerçevelerin Tasarım Optimizasyonu
No full textKonferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Çevre risk altında ve bu yüzden yapı mühendisliği tasarımı uzmanlık alanı yapılar için tasarım yaklaşımlarını dikkatli bir şekilde yeniden gözden geçirmelidir. Binaların yapısal sistemlerinde bulunan gömülü karbonun hatırı sayılır derecede önemli olduğu ve binaların çevresel etkilerinin zararlı olduğu tespit edilmiştir. Yapısal malzemeler çoğunlukla doğal kaynakları kullanır. Büyük miktarda karbon, yapısal malzemelerin çıkartılması, arıtılması ve kurulumu sırasında atmosfere yayılır. Soğuk şekillendirilmiş ince cidarlı çelik kesitlerin yapı elemanı olarak kullanılması, yapı sektörü için başlangıçta ki çevresel etkileri uzlaştırılmış yenilikçi, çevreci malzemeler ve uzun vadeli dayanıklılığa sahip sürdürülebilir (çevreci) yapı sistemleri sağlar. Bu makale, tasarım yönetmeliklerinde belirtilmiş olan sınırlayıcıları sağlayacak şekilde minimum çerçeve ağırlığına ulaşmak için soğuk şekillendirilmiş ince cidarlı çelik kesitleri elde eden bir tasarım algoritmasının geliştirilmesi ve iyileştirilmesi üzerine bir araştırmaya ışık tutamaktadır. Suni Arı Kolonisi (SAK) yöntemi geliştirilen tasarım algoritmasında çözüm aracı olarak kullanılmıştır. Bu yöntem, bal arısı kolonilerinin zeka davranışlarını taklit eden yeni optimizasyon yöntemlerinden biridir. SAK metodu ile yapılan en son çalışmalar, birleşimsel optimizasyon problemlerinin optimum çözümünü bulmada bu yöntemin etkinliğini ve sağlamlığını göstermiştir. Bir tasarım örneği geliştirilen optimum tasarım algoritmasının etkinliğini göstermek için eklenmiştir.The environment is at risk, and thus the structural engineering design profession needs to carefully reconsider design approaches to structures. Embodied carbon of structural systems in buildings has been established to be considerable and detrimental the environmental impact of the buildings. Structural materials use mostly natural resources. Large amounts of carbon are emitted into the atmosphere during the extraction, refinement, and installation of structural materials. Using cold-formed thin-walled steel sections as structural members provides a sustainable structures framework that reconciles initial environmental impacts of innovative, green materials and long-term durability for construction industry. This paper highlights a research on the development and implementation of a design algorithm to obtain cold-formed thin-walled steel sections in order to reach minimum frame weight while satisfying the constraints specified by design codes. Artificial Bee Colony (ABC) technique is used as a solution tool in improved design algorithm. This technique is a recent numerical optimization technique which mimics the intelligent behavior of honey bee swarm. The recent studies with the ABC method have shown its effectiveness and robustness in finding the optimum solution of combinatorial optimization problems. A design example is included to demonstrate the efficiency of the optimum design algorithm developed
Tek Katmanlı Yapraksı Kubbe Yapıların Harmoni Arama Yöntemi Kullanılarak Optimum Topoloji Boyutlandırması
No full textKonferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2010Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2010Tek katmanlı yapraksı kubbeler için harmoni arama yöntemine dayall optimum topoloji tasanm algoritmasl sunulmaktadlr. Bir müzisyenin daha iyi bir müzikal sunum arayl§l içinde uygulamaya çall§tlgl müzikal performans sürecine benzetilen harmoni arama yöntemi yakin geçmi§te geli§tirilen bir sayisal optimizasyon teknigidir. Caz dogaçlamasl, optimum çözüme ulaynaya çall§an optimum tasarlm stirecine benzer §ekilde, müzikal açldan tatmin edici uyumu bulmaya çabalar. Geliştirilen optimum tasarım algoritması, LRFD-AISC (Yük ve Dayanım Faktörü Tasarımı — Amerikan Çelik Tüzüğü Enstitüsü)'ye uygun olan davranış ve performans sınırlayıcılarını uygular. Optimum halka sayısı, tepe yüksekliği ve boru şeklindeki kesitler kubbe için tasarım değişkenleridir. Geliştirilen tasarım algoritması, bağlantı noktalarının ve eleman numaralandırılmalarının ve bağlantı noktalarının koordinat hesaplarının otomatik olarak yapılmasını L11kapsayan, kubbenin geometrik verilerini oluşturan bir yordama sahiptir. Kubbe yapılarda, narinlikten ve kusurların var olmasından dolayı bu yapıların dış yükler altında vereceği tepkiyi tahmin ederken geometrik doğrusalsızlığı göz önüne almak gerekmektedir. Dikkate alınan tasarım örneği sunulan algoritmanın etkinliğini göstermeyi amaçlamaktadır.Harmony search method based optimum topology design algorithm is presented for single layer lamella domes. The harmony search method is a numerical optimization technique developed recently that imitates the musical performance process which takes place when a musician searches for a better state of harmony. Jazz improvisation seeks to find musically pleasing harmony similar to the optimum design process which seeks to find the optimum solution. The optimum design algorithm developed imposes the behavioral and performance constraints in accordance with LRFD-AISC. The optimum number of rings, the height of the crown and the tubular cross-sectional designations for dome members are treated as design variables. The design algorithm developed has a routine that build the data for the geometry of the dome automatically that covers the numbering of joints, and member incidences, and the computation of the coordinates of joints. Due to the slenderness and the presence of imperfections in dome structures it is necessary to consider the geometric nonlinearity in the prediction of their response under the external loading. A design example is considered to demonstrate the efficiency of the algorithm presented
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