Damage identification of 1D and 2D structures based on modal curvature analysis

In this paper, experimental damage identification on 1D (beam) and 2D (plate) structures is carried out using methods based on the modal curvature and modal strain energy analysis. The considered techniques require setting a reference (intact) configuration the damaged structure is compared with. The type of damage analysed during tests consists in a local reduction of the beam or plate thickness properly produced with a milling machine. The calculation of modal strain energy needs the identification of the structural modes based on accelerometer data, which are obtained both with roving hammer technique and output-only technique, the latter suitable for continuous monitoring on ship structures in operational conditions. Though the exploited damage identification techniques were deeply analysed and compared in a previous work, their application to experimental data sets some challenges in terms of (i) numerical evaluation of strain energy in-tegrals and (ii) inclusion of additional points for the calculation of curvatures by exploiting nominal boundary conditions. The refinement of the considered procedure for damage identification is the preliminary step for a more practical application to continuous monitoring of ship structures which will follow in the near future to small size ships.