Optimum desing of passive control systems in building and bridge structures using metaheuristic search algorithms

Passive control systems are widely used for earthquake resistant structure design. Passive control systems, not only to improve the seismic performance of structural systems but also to protect the vibration-sensitive equipment. The design of passive control systems in buildings and bridges should be made elaborately to avoid any interruption in their service. In this study, 5 different nature-inspired metaheuristic algorithms were used to perform such sensitive design for passive control systems. Firstly, crow search algorithm (CSA), whale algorithm (WOA) and grey wolf algorithm (GWO) were employed to find the optimum isolation parameters of seismic isolated building and bridge substructure. In this context, the analytical model of a seismic isolated shear frame model and bridge substructure were developed. The aim is to obtain isolation system parameters that result the minimum roof / superstructure acceleration without exceeding the predefined isolator displacement and isolation damping limits. Metaheuristic algorithms were used for the optimal positions of viscous wall dampers in the next section. The number of viscous wall dampers, as well as their positions in the building, spans directly affects its seismic performance. Bat algorithm (BA) and dragonfly algorithm (DA) were adopted to achieve the minimum number of viscous wall dampers by placing the viscous wall dampers in the most suitable positions of the building. Floor accelerations and inter-story drift ratios were used as limits for the optimization of viscous wall dampers. The Matlab program was used for optimization operations together with the SAP2000 or Etabs program for structural analysis. The open application-programming interface (OAPI) was employed for the two programs to work together. Time history analyses were conducted using recorded near- and far-fault earthquake ground motions by linear and nonlinear methods. Optimum seismic isolation parameters and optimum positions for minimum number of viscous wall dampers were determined by using metaheuristic search algorithms.