An innovative approach to structural health monitoring through intelligent materials / Un approccio innovativo al monitoraggio strutturale tramite materiali intelligenti

Intelligent materials (or smart materials) are materials which can change their features in response to an external stimulus. Often, they show bidirectional effects from one physical domain to another and vice versa. As an example, piezoelectric elements generate voltage at their electrodes in response to strain, and vice versa. When an element made from an intelligent is coupled to a structure, the presence of this double effect allows defining a modal coupling coefficient expressing the efficiency of the energy conversion between the two considered physical domains (mechanical and electrical for the case of piezoelectric elements) at each eigenmode on the structure. Monitoring this modal coupling coefficient allows detecting the presence and location of structural damages without being affected by environmental and operational conditions, whch are main disturbing variables in structural health monitoring problems. This paves the way for a new feasible and reliable approach to structural health monitoring, also considering that additive manufacturing is enabling the construction of structural elements with embedded intelligent materials.