  We characterize the dynamical behavior of a clamped flexible fiber immersed
in wall turbulence over a wide range of natural frequencies by means of direct
numerical simulations. Only two flapping states are possible: one where the
fiber oscillates at the characteristic frequency of the largest turbulent
eddies and another where the natural structural response dominates. The former
is obtained in the more flexible cases, while the latter in the more rigid
ones. We observe here for the first time that in the turbulence dominated
regime the fiber always sways at a frequency proportional to the largest scale
of the flow, regardless of its structural parameters. The hindrance of the
clamp to the wall prevents the synchronization of the fiber with turbulent
eddies of comparable size.
