Binary Flutter of Suspension Bridge Deck Sections

Wind tunnel experiments on models of suspension bridge deck sections with plate girders of various heights are made to show that binary flutter of suspension bridge deck sections can be classified into three types which have different mechanisms of excitation; i.e., the classical type flutter, the single-degree-of-freedom type, and the intermediate type. Analyses on an energy equation of bluff structures with many degrees-of-freedom are also given to establish the theoretical basis of the classification of binary flutter. Although the geometry of the deck section is found to be the most dominant parameter that influences the type of flutter, it may also depend on various other parameters. The uncoupled frequency ratio is chosen, among others, and its effects on the three types of binary flutter are investigated.