Passive monitoring of structures using deconvolution-reconstructed waves

The passively reconstructed Impulse Response Function (IRF) (or Green's function) between two points of a medium can return a wealth of information about the dynamic behavior of the system including the existence of defects. For a linear system subjected to an unknown excitation source, the deconvolution operation between two monitored points can properly reconstruct the IRF between the two points, effectively using one of the points as a "virtual" source. This technique has been successfully used for studying the global dynamic behavior of structural systems, such as buildings and bridges, in the low frequency range. In civil engineering this approach is often referred to as Seismic Interferometry (SI). Various studies using SI have discussed the high frequency regime of transient wave propagation. This paper will focus on this high frequency regime and propose some novel implementations of SI to detect local structural damage in multistory buildings. Results will be presented from an aluminum rod and a laboratory-scale multistory aluminum frame.