Wireless Piezoelectric Sensor Systems for Defect Detection and Localization

Defect detection is an emerging field in SHM, which not only reduces costs by minimizing maintenance and inspection cycles, but also prevents catastrophic failures at an earlier stage. As a non-destructive evaluation method, the well-known Lamb wave-based defect detection and localization approach has been widely used in SHM. Due to its unique features of simplicity, durability, small size and low-cost, piezoelectric lead zirconate titanate (PZT)-based Lamb-wave monitoring technology has shown great promise for defect detection in SHM. This chapter presents the basic principles of Lamb wave-based defect detection and active PZT sensing. It introduces the newly developed wireless PZT sensor network for SHM, followed by the detailed design of the wireless PZT sensor nodes. The chapter discusses the procedure for distributed signal processing for SHM. The effectiveness and applicability of acoustic PZT monitoring were evaluated in both experimental and numerical investigations for three types of representative bridge: steel-girder, reinforced concrete and pre-stressed concrete.