Structural Health Monitoring of Composite Materials Using Piezoelectric Sensors

Structural Health Monitoring (SHM) denotes a system with the ability to detect and interpret adverse " changes " in a structure in order to improve reliability and reduce life-cycle costs. The greatest challenge in designing a SHM system is knowing what " changes " to look for and how to identify them. This paper focuses on the relationship between sensing systems and their ability to detect changes in a structure's behavior. Experimental and analytical results are presented for in-situ damage detection of composite materials using piezoceramic sensors. Modal analysis methods have proven reliable for detecting small amounts of global damage in composite structures. By comparison, Lamb wave methods were sensitive to all types of local damage, and present the possibility of estimating damage location. Piezoelectrics could also be used as multipurpose sensors to detect damage using a variety of other methods including acoustic emission and strain monitoring simultaneously by altering driving frequencies and sampling rates. This paper also presents a recommendation for the design of a SHM system architecture. These systems will be an important component in future designs of air and spacecraft to increase the feasibility of their missions.