The present work deals with the unsteady galloping instability, which arises at low reduced flow velocities, for steel-concrete composite bridge decks during the incremental launching phase. In this particular situation, the light weight and bluff shape of the steel box, which is normally first launched, imply a high proneness to the risk of unsteady galloping. The main goal of this thesis is to understand the unsteady galloping with respect to these special cross sections, which have not been investigated in depth before, and to develop an analytical approach for the modeling of unsteady galloping as a basis for design of bridges.weiterlesen