Augmenting continuous damage sensing in concrete structures using conformal flexible piezoelectric skin

When transducers are integrated with concrete structures for condition monitoring, conventional lead zirconate titanate-based transducers, due to their inherent brittleness, unfortunately, are prone to interference from structural strains and deformations induced by external loads, restricting their effectiveness in continuous damage monitoring. With this motivation, this work designs a flexible piezoelectric skin (FPS) that exploits the unique properties of the macro fiber composites (MFCs), including their architectural simplicity, scalability and excellent flexibility. The MFCs serve as the foundational transceiver elements, enabling damage sensing in concrete structures under varying loading conditions. Assisted with the defined general damage sensitive index, the FPS is able to capture critical damage signatures to track damage progression of the monitored area, offering continuous and reliable damage evaluation. The experimental explorations demonstrate that the MFC array-based FPS possesses active damage sensing capabilities on concrete interfaces while delivering promising performance in terms of flexibility, sensitivity, and reliability. The conformal FPS serves as a feasible strategy for continuous condition monitoring of concrete structures, facilitating long-term structural integrity assessment in civil engineering applications.