Active control for a benchmark building under wind excitations

The tall building proposed in the benchmark problem is a concrete office tower, which is wind sensitive due to its slenderness. The wind loads acting on the building are defined by the results of wind tunnel tests conducted at the Sydney University and an active mass driver can be designed for installation on the top floor in order to reduce the structural response under strong wind gusts. In this paper, the control strategy presented for the third generation benchmark control problem for wind-excited buildings (J. Eng. Mech. (1999), submitted for publication) is the simultaneous treatment of both H₂ performance criteria and H_∞ attenuation constraints that demonstrates design tradeoffs and can be applied to the AMD system based on acceleration feedbacks. This control problem can be formulated by linear matrix inequalities in terms of a common Lyapunovfunction. Solving linear matrix inequalities is a convex optimization problem and efficient interior-point algorithms are now available to solve this problem. Simulation and design results demonstrates that, decreasing H_∞ attenuation constraint can be used to reduce the structural response under wind excitations at the expense of increasing H₂ performance index.