Gravity Load Effects on Inelastic Simulation of Buildings Subjected to Wind Loads

Abstract

Reduced-order (single-degree-of-freedom) models of buildings subjected to wind loads were analyzed to determine the effect of gravity loads on inelastic behavior. The lateral wind loads were based on data from atmospheric boundary layer wind tunnel tests to capture the temporal and spatial variation of wind pressure on a building envelope. The lateral load resisting system of the building was idealized using a bilinear relationship, and gravity load effects were introduced using a stability coefficient. Nonlinear response history analyses were solved using direct implicit integration of the equation of motion, and an energy balance was used to assess the quality of the numerical solution. The resulting response histories were used to interrogate the relationship between inelastic displacement, ductility, period of vibration, and gravity loads. The results indicate that inelastic displacements were approximately equal to the elastic displacements even in the presence of gravity loads for cross wind excitation. For along wind excitation, the inelastic displacements were approximately equal to the elastic displacements regardless of gravity loads. The findings suggest that the equal displacement concept may have application to the wind design of high-rise buildings where cross-wind loads control the design of the lateral system

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