Structural Health Monitoring of a Composite Panel Based on PZT Sensors and a Transfer Impedance Framework

Abstract

One of the ideas for development of Structural Health Monitoring (SHM) systems is based on excitation of elastic waves by a network of PZT piezoelectric transducers integrated with the structure. In the paper, a variant of the so-called Transfer Impedance (TI) approach to SHM is followed. Signal characteristics, called the Damage Indices (DIs), were proposed for data presentation and analysis. The idea underlying the definition of DIs was to maintain most of the information carried by the voltage induced on PZT sensors by elastic waves. In particular, the DIs proposed in the paper should be sensitive to all types of damage which can influence the amplitude or the phase of the voltage induced on the sensor. Properties of the proposed DIs were investigated experimentally using a GFRP composite panel equipped with PZT networks attached to its surface and embedded into its internal structure. Repeatability and stability of DI indications under controlled conditions were verified in tests. Also, some performance indicators for surface-attached and structure-embedded sensors were obtained. The DIs’ behavior was dependent mostly on the presence of a simulated damage in the structure. Anisotropy of mechanical properties of the specimen, geometrical properties of PZT network as well as, to some extent, the technology of sensor integration with the structure were irrelevant for damage indication. This property enables the method to be used for damage detection and classification.

Microcapsule encapsulated with leuco dye as a visual sensor for concrete damage indicationviacolor variation

“…Structural health monitoring (SHM) technologies to monitor damage are applied extensively throughout civil engineering. 2,3 Since micro-cracks are hardly visible to the naked eye, specialized instruments such as optic ber sensors, 4,5 piezoelectric sensors [6][7][8][9] and data processing equipment are required for traditional SHM technology.…”

Monitoring of Grouting Compactness in Tendon Duct Using Multi-Sensing Electro-Mechanical Impedance Method

“…In addition, various packaging and protection methods have been developed for PZT transducers [36][37][38] so that they can be easily deployed for real-time structural monitoring through embedment for concrete structures [39][40][41] or surface bonding for steel structures, concrete structures, and composite structures [42,43]. PZT-based structural health monitoring methods include the active sensing approach [44][45][46][47], electro-mechanical impedance (EMI) approach [48][49][50], and passive sensing method [51][52][53].…”

An Innovative Diagnostic Film for Structural Health Monitoring of Metallic and Composite Structures

“…Other challenges related to the durability, longevity, and reliability of the installation and operation of onboard equipment are reported in Radio Technical Commission for Aeronautics (RTCA) DO-160C [ 10 ]. Despite the fact that permanently attached PZT networks have proven to be a reliable tool for detecting and localizing impacts [ 11 , 12 , 13 ] and resulting damage (i.e., delamination) [ 14 , 15 , 16 , 17 ] in composite structures in laboratory conditions, certain issues arise when this technology is scaled up to real structures in the aviation industry [ 18 ]. More specifically, the required SHM system for monitoring the structural integrity of an aerospace structure consists of ground components, which remain on the ground, and onboard (airborne) components, which are permanently installed on the structure [ 19 ].…”