A study on Aerodynamic Instability of Rectangular Cylinder with Changing Side Opening Shapes

Abstract

It is known that the side opening affects the aerodynamic vibration characteristics in a rectangular cylinder with B/D = 2, which imitates a butterfly web bridge. Therefore, we conducted experiment to investigate the aerodynamic vibration characteristics of a rectangular cylinder with side openings. We used two different opening shapes. One is opening shape with alternating distribution of openings and closures in the span direction, and the other is two-dimensional opening shape that eliminates structural three-dimensionality. As a result, it was found that the larger the opening ratio, the higher the wind speed at which galloping occurs, and the excitation force of the galloping reached a maximum value at a certain opening ratio.