Suni Arı Kolonisi Yöntemi Kullanılarak Soğuk Şekillendirilmiş İnce Cidarlı Çelik Kesitlerden Yapılan Az Katlı Çelik Çerçevelerin Tasarım Optimizasyonu

Konferans 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

Ant colony optimization of shielding for mixed neutron and gamma radiations

Shielding is important in maintaining safe levels of radiation. In mixed neutrons and gamma-rays condition, more than one material are needed for shielding purposes. These materials can be arranged into a multilayer shield or they can be mixed into a composite shield. These shields have different variables and it can be increasingly complex to optimise them. In such a situation, using brute method is infeasible in terms of computation time. Recent studies have been looking into the use of metaheuristics in shield optimisation specifically the genetic algorithm (GA). This study extends the knowledge by investigating the ant colony optimisation (ACO) for shielding optimisation against mixed radiation. Three objectives were outlined: to develop an ACO-based algorithm to optimise a shield made from polyethylene (PE), boron, and tungsten, to build a GA as a comparison, and to evaluate the new shield design. MCNP5 was used for shielding calculations. There were four problem cases: a composite shield with known solution (Case 1); a composite shield with unknown solution (Case 1.2); a multilayer shield with known solution (Case 2); and a multilayer shield with unknown solution (Case 2.2). Six ACO parameters and four GA parameters were tested to observe their effects and to determine their best values for the optimisation algorithms. Four composite shields were fabricated and experimented with a 252Cf mixed neutron-gamma source. It was observed that the ACO-MCNP algorithm was significantly better than the brute method. It managed to find the exact solutions for Case 1 and Case 2 while reducing the runtime of the brute method by 81.75% and 89.01% respectively. For Case 1.2 and Case 2.2, good solutions were achieved in only 2.13 hours and 1.28 hours respectively as compared to the brute method which could take almost 70 hours to complete. The results also suggest that the ACO is a good alternative to the GA for shielding optimisation. For the experimental work, it was found that the PE composite with additives of 16 wt% boron and 16 wt% tungsten had the best mixed radiation shielding performance as compared to pure polyethylene, poly-boron (25 wt%), and poly-tungsten (25 wt%)

Ant colony optimization of irregular steel frames including elemental warping effect

The effect of warping in the design of steel space frames having members of thin walled steel sections is significant. In this paper 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 technique is used to obtain the solution of the design problem. A number of space frame examples are designed by the algorithm developed in order to demonstrate the effect of warping in the optimum design. (C) 2011 Civil-Comp Ltd and Elsevier Ltd. All rights reserved

Modelos de comportamiento seccional de hormigón armado ajustados a ensayos mediante algoritmos metaheurísticos

[SPA] En la tesis doctoral "Modelos de comportamiento seccional de hormigón armado ajustados a ensayos mediante algoritmos metaheurísticos" se proponen unas expresiones de comportamiento seccional capaces de proporcionar aspectos relativos a los estados de plastificación y último de secciones rectangulares de hormigón armado, como son el momento, la curvatura y el giro. Dichas expresiones se obtienen calibrando unas expresiones previamente propuestas en la literatura científica con ensayos experimentales correspondientes a vigas y pilares de sección rectangular. En el proceso de calibración se emplean técnicas de optimización basadas en algoritmos metaheurísticos.[ENG] Modelling concrete structures requires the implementation of numerical models capable of reproducing the nonlinearity of this problem adequately. In particular, the seismic behaviour of these structures requires the application of different types of models, such as models of sectional behaviour, hysteresis models and global models, being the interaction between them essential to simulate the problem in an integral way. Seismic analysis of structures is a really time-consuming process, so that the models involved need to be accurate and efficient from the point of view of computing time. Therefore, it is important to obtain simple expressions that adequately reproduce the yield and ultimate behaviour of reinforced concrete sections, which is necessary to define the properties of the plastic hinges generated in the structure when acting the seismic load. Obtaining these expressions involves proper calibration with experimental tests. In particular, if these expressions must be calibrated by an extensive database, specific numerical procedures are required, such as those based on optimization techniques, in order to achieve an optimum adjustment between the values offered by the expressions and the experimental results. In this thesis, a database composed by more than 1000 experimental tests has been analysed and a set of tests is selected such that meet with seismic and construction requirements listed in the main construction codes; several empirical expressions relating to yielding and ultimate state of rectangular reinforced concrete sections have been calibrated; and the expressions obtained are implemented in the nonlinear analysis of several reinforced concrete frames, comparing the results obtained with different methods.Universidad Politécnica de CartagenaPrograma de doctorado en Medio Ambiente y Minería Sostenibl