Multi-objective Optimization Of Seismic Frame Structures Based On Quick Group Search Optimizer

In recent years, the structural optimization algorithm based on swarm intelligence that is a new evolutionary computation technique appeared, which is more scientific and reasonable than traditional optimization design, making the structure safe, reliable and economical and reasonable. Especially when dealing with more complex design optimization. For example, swarm intelligence algorithms show a lot of advantages in solving highly nonlinear, multi-constraint, multi-extremum problems. It is easy to understand and implement. In many optimization problems, the swarm intelligence algorithms have been widely used and researchers increasingly focus swarm intelligence algorithm.A quick group search optimizer (QGSO) is an intelligent optimization algorithm which has been applied in structural optimal design, such as widely used in the hinge space structural system, whose preferable convergence accuracy and rate is presented to deal with a space structure system. A multi-objective quick group search optimizer (MQGSO) based on quick group search optimizer (QGSO) was presented in the paper. The MQGSO algorithm combines the Pareto optimal solution theory and crowding distance mechanism, which is suitable for multi-objective structure optimization design, simple and practical; the QGSO algorithm used a coding feature like the GSO algorithm and the PSO algorithm, therefor, the optimization for seismic design has high efficiency and fast convergence.It is the first time that QGSO algorithm optimization is adopted in aseismic resistance research of steel frames with semi-rigid connections which more accurately reflect the actual situation, then improve it into a multi-objective algorithm (MQGSO) for multi-objective optimization of static and dynamic structural design. The MQGSO algorithm is applied to the cross-section optimization of a10-bar planar truss structure and two-bay five-layer steel frame; the shape optimization of a25-bar spatial truss structures. Taking the weight and dynamic strain as design objectives, the aseismic optimal design of a three-bay six-layer steel framework was carried out with the MQGSO algorithm. It has been applied to the large-span space structures such as the double-layer spherical shell. The minimum values of both the displacement and total weight of the shell structure are set as the optimization goals. In the seismic design optimization, the response spectrum method and time history analysis are adopted in this paper. The MATLAB computational analysis is in the form of a combination with ANSYS to optimize the structure of the seismic structure extends from the planar structure to the cross-spatial structure. The final results of the optimization algorithm were compared with the IMGSO algorithm and the MGSO algorithm. The Pareto frontier was provided that the feasible solution can be used for practical optimization design.