Nonlinear dynamic analysis of slender reinforced concrete structures subjected to wind loading

The goal of this paper is to propose a non-linear dynamic model based on experimental data and NBR-6123:1987 [1] to accomplish a non-linear dynamic analysis of slender structures subjected to wind loading. Several tests were conducted do asses the effective stiffness of slender structures as function of the internal loads. Once we have one equation to represent the real stiffness we proceed the dynamic analysis. At first we compute the static response given by the mean wind speed. In this part of the problem we consider the concept of effective stiffness to represent the physical non-linearity of material and a P-Delta method to represent the geometrical non-linearity. Considering the final stiffness obtained in that P-Delta method we compute the dynamic response given by the floating wind speed, according to the discrete dynamic model given by NBR-6123: 1987 [1]. A 40 m RC telecommunication tower was analyzed and the results obtained were compared with those given by linear static and dynamic models. We conclude that the non-linear dynamic analysis proposed here leads to values of internal loads 15% larger than the traditional linear dynamic analysis and 50% larger than the static analysis.