Application of vibration based technique in health monitoring of multi-stable laminated composites

This paper deals with the problem of vibration based health monitoring (VHM) in multi-stable asymmetrical laminated composite structures. Multi-stable asymmetrical laminates can be snapped between two or more geometries. The ability of snapping between two or more geometries in multi-stable composite structures makes them vulnerable to delaminate. Because of these reason early detection of damage in these systems during their service life is receiving increasing attention. In the present work, an efficient and accurate finite element model (FEM) based on layer-wise theory by considering the electro-mechanical coupling effect has been developed to investigate the actuation and /or sensing mechanism of extensional piezoelectric surface bonded as patches in a composite laminate. Then the developed FEM has been implemented in an asymmetrical laminate to investigate the frequency and voltage responses of both intact and damaged models by considering the delamination growth.