Marco Gherlone

This work investigates the use of the inverse Finite Element Method (iFEM) for damage localisatio...n by reconstructing the damaged strain field of the structure. The iFEM is a proven technique for reconstructing the displacement field of a structure using surface strain measurements from discrete locations on the structure.

Methods for real-time reconstruction of structural displacements using measured strain data is an... area of active research due to its potential application for Structural Health Monitoring (SHM) and morphing structure control.

The inverse Finite Element Method (iFEM) is applied to reconstruct the displacement field of a shell structure which undergoes large deformations using discreet strain measurements as the prescribed data. The iFEM computations are carried out using an incremental procedure where at each load step, the incremental strains are used to evaluate the incremental displacements which in turn update the geometry of the deformed structure.

A crack or a localized damage in a structure provokes a discontinuity in the rotation. Consequently, mode-shapes are nonsmooth at the damage position and the first derivative (strictly related to the rotation) presents a jump discontinuity. Based on this simple concept, a new approach has been developed in order to predict the location of the mode-shape derivative discontinuities, and therefore the location of damage, without the need to directly differentiate.