Damage localisation in thin plates using the inverse Finite Element Method

This work investigates the use of the inverse Finite Element Method (iFEM) for damage localisation 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. This new approach divides a large structure into square grid cells with strain sensors located only at the boundaries of these cells. Presence of a crack in a cell causes perturbations in the strain measurements at the boundary. The iFEM reconstructed strain field will show a higher strain magnitude in those cells affected by damage in comparison to healthy, unaffected cells of the structure. Using such a relative rather than absolute measure of strain for damage localisation helps to reduce the number of strain sensors required for the Structural Health Monitoring (SHM) of large structures.