교량기본단면의 와류진동에 미치는 난류효과에 대한구조감쇠의 영향

Abstract

This study is focused on the effects of turbulence characteristics on the vortex-induced response of basic bridge sections with change of structural damping. Turbulent flows are generated using an active simulation method controling turbulence characteristics independently. The response tests for two dimensional models are carried out in turbulent flows and smooth flow, where the structural damping of models are varied by electromagnetic dampers. Employed sectional shapes of models are the rectangular shape with aspect ratio of 2 (Model-A) and hexagonal shape (Model-AF). As the results of experiments, the maximum amplitude of vortex-induced response of Model A is decreased with increasement of turbulent intensity and that is more significant in the state of higher damping. In the case of Model-AF, the turbulence effects to the maximum amplitude of vortex induced oscillation are not so strong compare to Model-A, however the occurrence area in V-A curves is reduced by the existence of wind velocity fluctuations. As the structural damping increases, the response of Model-AF is decreased with the increasement of turbulence intensity. The change of turbulence scale does not affect the vortex induced response of Model-A and AF.