Along-Wind Aero-Elasticity of High-Rise Buildings by Using Indirect Forced Actuation Technique

Abstract

The frequency-dependent aerodynamic damping and stiffness of high-rise buildings in along-wind motion have been systematically investigated and compared through wind tunnel tests under smooth wind flow. A novel identification scheme based on the indirect forced actuation technique was developed, involving only a simple curve-fitting technique on the frequency response function induced by the actuation. To ensure that global minimization in curve-fitting was achieved, a genetic algorithm and a conventional gradient search method were used in obtaining the final results. An alternative derivation of the frequency response function via the time-domain state space equation is also presented, which has the supporting advantage that the simulation of time history of the structural response becomes possible. To demonstrate the approach, various prism models representing different high-rise buildings with varied aspect ratios and height-width ratios were used in the experimental identification. A total of nine mo...