Optimal placement of viscous wall dampers in RC moment resisting frames using metaheuristic search methods

Abstract

Viscous wall dampers (VWDs) are one of the most effective energy dissipation devices for the seismic performance enhancement of buildings. The number of VWDs as well as their positions in the building directly affects the seismic performance. In this study, two of the metaheuristic algorithms were employed for the optimal placement of VWDs in a reinforced concrete (RC) special moment resisting frame (SMRF) in order to achieve a safe yet cost effective solution. Bat algorithm (BA) and dragonfly algorithm (DA) were adopted to achieve the minimum number of VWDs by placing them in the most suitable positions of a 15 story RC SMRF. The floor accelerations and inter-story drift ratios (ISDRs) are considered as the constraints for the position optimization of VWDs with the objective of minimum number of VWDs. The application-programming interface (API) was employed for the interaction and data transfer between the structural analysis program ETABS and the Matlab program for optimization operations. Nonlinear response history analyses (NRHA) were conducted using recorded earthquake ground motions. Optimal placement for the minimum number of VWDs was achieved by using metaheuristic search algorithms. The additional damping provided by VWDs is effective in reducing the max ISDRs. However, higher damping ratios do not always result in the minimum floor accelerations. Therefore, an optimum damping ratio provided by VWDs needs to be sought for achieving minimum floor accelerations.