Erkan DOGAN, Ferhat ERDAL, Mehmet Polat SAKA

THE EFFECT OF MEMBER GROUPING ON THE OPTIMUM DESIGN OF GRILLAGES VIA SEARCH TECHNIQUES

Eleman guruplandırması çelik ızgara sistemlerin minimum ağırlık tasarımında önemli etkiye sahiptir. Mevcut çalışmada bu etki parçacık küme ve armoni arama isimleriyle bilinen iki farklı olasılığa dayalı optimizasyon metodu yardımıyla incelenmiştir. Izgara sistemin optimum tasarımı LRFD-AISC Amerikan şartnamesinde bulunan sınırlayıcıların dikkate alınması suretiyle gerçekleştirilmiştir. Her iki eksen doğrultusunda tasarlanacak olan elemanlar için aynı şartnamede bulunan 272 adet geniş başlıklı çelik profil kesiti kullanılmıştır. Optimum tasarım algoritması ızgara sistem elemanları için 272 adet çelik profilin bulunduğu tasarım havuzundan uygun profillerin seçilmesi suretiyle, sınılayıcıların sağlandığı ve ağırlığın minimum olduğu tasarımı belirleyecek şekilde oluşturulmuştur. Paçacık küme ve armoni arama yöntemlerinin kullanılmasıyla elde edilen tasarım algoritmaları yardımıyla sözkonusu kesikli optimizasyon probleminin çözümü gerçekleştirilmiştir. Bir tasarım örneği dikkate alınarak kiriş yerleşim aralıkları ile optimizasyon metodlarının performanslarının optimum tasarıma etkisi incelenmiştir.

THE EFFECT OF MEMBER GROUPING ON THE OPTIMUM DESIGN OF GRILLAGES VIA SEARCH TECHNIQUES

Member grouping of a steel grillage system has an important effect in the minimum weight design of these systems. In the present research, this effect is investigated using an optimum design algorithm which is based on two stochastic search techniques called particle swarm (PSO) and harmony search (HS) optimization methods. The optimum design problem of a grillage system is formulated by implementing LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Construction) limitations. It is decided that W-Sections are to be adapted for the longitudinal and transverse beams of the grillage system. 272 W-Section beams given in LRFD code are collected in a pool and the optimum design algorithm is expected to select the appropriate sections from this pool so that the weight of the grillage is the minimum correspondingly the design limitations implemented from the design code are satisfied. The solution for this discrete programming problem is determined by using the PSO and HS algorithms. Design example is presented to demonstrate the effect of beam spacing and performances of stochastic search techniques in the optimum design of grillage systems.

Keywords:

Grillage optimization, discrete optimum design, member grouping stochastic search techniques, particle swarm algorithm, harmony search algorithm,

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