Structures with Surface-Bonded PZT Piezoelectric Patches: a BEM Investigation into the Strain-transfer Mechanism for SHM applications

In this work a three-dimensional BEM model is used for the analysis of structures with cracks and surface bonded piezoelectric PZT patches used as strain sensors. The cracked structure is modelled by the dual boundary element method, which allows for accurate and reliable crack analysis, while the piezoelectric patch is analyzed by a finite element state-space approach, that embodies both the full electro-mechanical coupling and the suitable sensor’s boundary conditions. The model is used to investigate the strain-transfer mechanism from an host elastic structure to the piezoelectric layer, taking into account the effect of the adhesive layer, as well as the mechanical interaction between the sensor and the measured field. Finally, a fast solver based on the use of the GMRES and the hierarchical matrices is employed to speed up the solution of some large scale BEM systems arising from structural health monitoring applications. The numerical tool has been used to investigate the sensitivity of sensors arrangements in three-dimensional damaged solids.