# Description

In this example, a rigid H profile bridge is considered based on the model by [2] and used in [1] . It is supported with a rotational and a vertical translation linear elastic spring. The horizontal motion is fixed to zero. The rigid body is exposed to uniform fluid flow in the horizontal direction. Bridge oscillations may consequently occur due to vertical or rotational galloping. Coupled galloping of two or more degrees of freedom is commonly known as flutter [1].

It appears clearly that the rotation is the dominant motion with severe oscillations. This is further confirmed by the rotational and translation frequencies which coincide at f0 = 0.183s which is close to the natural rotational frequency fθ = 0.200s and fy = 0.13s. The amplitude of the rotations is max(θ) = 57◦ and the maximum vertical displacement is obtained as 0.72 ≤ max(Y ) ≤ 0.84 which is again is very good agreement with the results by [1].

References :

[1] W. Dettmer and D. Peric, A computational framework for fluid-rigid body interaction: Finite element formulation and applications, Computer methods in applied mechanics and engineering, 195 (2006), pp. 1633–1666.

[2] B. Hubner, E. Walhorn, and D. Dinkler, Strongly coupled analysis of fluid structure interaction using space-time finite elements, ECCM, 2001.