  Based on the physics of stochastic processes we present a new approach for
structural health monitoring. We show that the new method allows for an in-situ
analysis of the elastic features of a mechanical structure even for realistic
excitations with correlated noise as it appears in real-world situations. In
particular an experimental set-up of undamaged and damaged beam structures was
exposed to a noisy excitation under turbulent wind conditions. The method of
reconstructing stochastic equations from measured data has been extended to
realistic noisy excitations like those given here. In our analysis the
deterministic part is separated from the stochastic dynamics of the system and
we show that the slope of the deterministic part, which is linked to mechanical
features of the material, changes sensitively with increasing damage. The
results are more significant than corresponding changes in eigenfrequencies, as
commonly used for structural health monitoring.
