Multi-objective optimization of a structural link for a linked tall building system

This study presents the optimal location and properties (e.g., mass and stiffness) of structural links for LB systems. The objective is to minimize wind-induced displacement responses as well as wind-induced acceleration responses of LB systems. A series of wind tunnel tests were conducted in which wind loads were measured for varying distances between LBs. A genetic algorithm and a three-dimensional analytical model were then used to determine the optimal link location and properties that would minimize the two wind-induced responses. The results show that adding a mass in the link tends to increase the displacement responses but decreases the acceleration of LBs and placing the link between 0.7 and 1 (i.e., top) of the buildings is optimal. As the link moves from 0.7 to the top of the buildings, the acceleration response decreases in general, but the displacement response increases. Additional link stiffness, on the other hand, generally decreases both responses. However, this additional stiffness must not be very large. The optimal gap distance should be half the breadth of the building. The results of this study provide practical guidance for practicing engineers and can be used to ensure safety in the design of tall linked building systems.