Integrated wind-induced response analysis and design optimization of tall steel buildings using Micro-GA

SUMMARY This paper presents an integrated procedure for wind-induced response analysis and design optimization for rectangular steel tall buildings based on the random vibration theory and automatic least cost design optimization technique using Micro-Genetic Algorithm (GA). The developed approach can predict wind-induced drift and acceleration responses for serviceability design of a tall building; the technique can also provide an optimal resizing design of the building under wind loads to achieve cost-efficient design. The empirical formulas of wind force spectra obtained from simultaneous measurements of surface pressures on various rectangular tall building models in wind tunnel tests are verified testified using a published example. Upon the known wind force spectra, the equivalent static wind loads for every storey, such as along-wind, across-wind and torsional loads, are then determined and applied for structural analysis including estimation of wind-induced responses. An improved form of GAs, a Micro-GA, is adopted to minimize the structural cost/weight of steel buildings subject to top acceleration and lateral drifts constraints with respect to the discrete design variables of steel section sizes. The application and effectiveness of the developed integrated wind-induced response analysis and design optimization procedure is illustrated through a 30-storey rectangular steel building example. Copyright © 2009 John Wiley & Sons, Ltd.