INFLUENCE OF NATURAL PERIOD AND DAMPING RATIO ERRORS ON WIND FORCES OF A TALL BUILDING ESTIMATED BY MODAL ANALYSIS

Abstract

Modern structures are more susceptible to larger dynamic excitation brought about by stronger wind forces. For this reason, accurate estimation of the actual wind loads acting on the structure has become greatly necessary. Also, important dynamic parameters of the building, particularly natural period and damping ratio are considered to be highly uncertain and may contribute additional errors in the estimation of wind forces. Hence, the effect of uncertainty in the evaluation of these dynamic parameters to the estimated wind forces must also be given more careful consideration. This paper investigates the accuracy of modal analysis in estimating the wind forces acting upon a 10 degree-of-freedom model and determines the sensitivity of these estimated wind forces when errors in the natural period and damping ratio are introduced.