Analysis of the effect of the stiffeners on the load bearing capacities of cellular beams with the finite element method

Cellular beams have gained increasing interest as an effective steel construction model since their inception. The most important feature of these beams is that they increase the height, moment of inertia and cross-section coefficient compared to normal form steel beams with the same profile section. Cellular beams are also used as roof and floor beams to easily cross wide openings. They also give ideal results in sloping roof design by reducing weight and cost. In the proposed study, optimum dimensioning of cellular beams, determination of their carrying capacity under load and their comparative analysis with finite element method were made. The effect of the reinforcing plates on the load-bearing capacity of these beams was also examined within the scope of the thesis. The first phase of the thesis research focused on optimum sizing of cellular beams using harmony search and particle swarm techniques. These methods provide the design limitations defined in the regulation by choosing the appropriate profile among the IPN sections and minimize the weight of the system. In the experimental process, which is the second stage of the study; In the first part, the strength of 8 IPN cross-section cellular beams under pressure cylinder with hydraulic power unit was tested. Depending on the local buckling and moment-shear transfer evaluations of the horizontal, vertical and circular stiffeners plates placed around the cavities, the effect of the body span steel beams on the final load-carrying capacity was also examined in detail. Finally, the load-carrying capacity and nonlinear behavior of the experimental cellular beams were compared with the finite element method using the data obtained from the experimental studies. In light of the results obtained, it is aimed to use steel beams in practical applications and to use optimization methods widely in structural design.