Using the component method to optimize the cost of end plate connection in 2D steel frames using particle swarm optimization

Due to the increasing use of steel frames in buildings built in Iran and the increase in the price of profiles compared to raw sheets, the use of plate girders in the construction of steel frames has become significantly popular. Connections are one of the basic components in all structures, including steel structures, and are considered the main factor in the integrity of structural systems. The purpose of this research is to determine the optimal dimensions for the end plate connections to reduce the cost using particle swarm optimization algorithm, so that the mechanical limitations related to the bending moment and the resulting initial stiffness, as well as the safety and integrity of the connection, are not compromised. In the optimization model, six design variables including the dimensions and thickness of the end plate, the diameter and location of the bolts were selected to compare the obtained values with the results of the past literature. To calculate the bending moment and rotational stiffness of the connection, the "component method" found in Eurocode 3-part 1-8 was used, and the analysis and optimal design of beam-to-column connections for two-dimensional steel frames was done in the MATLAB computing environment. The output of this program shows completely satisfactory results compared to the results in the past literature, so that the results obtained by using the aforementioned optimization algorithm show the cost of connections A, B, C and D of the investigated frame, respectively cost reductions of 46.24%, 5.29%, 55.10% and 56.44% by compared to the research of Cabrero and Bayo in 2005. Also, the cost of connections A and C of the examined frame decreased by 8.07% and 0.22%, respectively, compared to Diaz et al.'s research in 2012.