Structural health monitoring of a plate excited by ambient load by wavelet transform
Use of environmental loads to perform continuous Structural Health Monitoring (SHM)
allows controlling the structural integrity in operative conditions, with considerable
timesaving and safety benefits. Aim of this paper is the identification of the damage on a plate
excited by potential vortices using the Continuous Wavelet Transform (CWT). The numerical
model of the load is based on the relationship between the induced vortex pressure and a
rigid wall. The numerical model of the damaged plate is determined by a Finite Element (FE)
technique. Eigenvalues and eigenvectors are extracted by the FE solution and they are used
to calculate the physical response after by means of the generalized coordinates. An index,
based on the analysis of the CWT coefficients, is defined to identify the position of the
damage. The proposed index allows detecting the actual damage position with good accuracy
and does not require the knowledge of the response of the undamaged plate. In order to study
the sensitivity of the index the analysis is performed on a set of different damage amplitudes
and positions.