Affiliations: [a] The State Key Laboratory of Mechanics and Control of
Mechanical Structures, Nanjing University of Aeronautics and Astronautics,
Nanjing, Jiangsu, China
Correspondence:
[*]
Corresponding author: Shenfang Yuan, The State Key Laboratory of
Mechanics and Control of Mechanical Structures, Nanjing University of
Aeronautics and Astronautics, Nanjing, Jiangsu, China. E-mail: [email protected]
Abstract: Structural health monitoring (SHM) technology is a reliable,
efficient and economical approach to increase the safety and reduce the
maintenance cost of high performance structures. Among the existing SHM
methods, piezoelectric transducers (PZTs) array and Lamb wave based SHM methods
are sensitive to small damage and studied by many researchers. In this paper,
aiming at developing a practical method for on-line localization of damage and
impact on aircraft composite structure which can take advantage of time
reversal focusing and does not rely on the transfer function, a phase synthesis
based time reversal focusing method is proposed and a twin-PZTs array
arrangement based damage imaging method is discussed first. In this method,
damage and impact images are given out directly through time reversal focusing
and the other imaging processes such as the delay-and-sum imaging method
adopted in many researches of time reversal focusing are not needed. And then,
a kind of PZTs smart layer (PSL) with electromagnetic shielding is developed.
For real application of SHM, an integrated multi-channel scanning system (ISS)
with impact and damage monitoring function is developed thirdly. The ISS can
scan large numbers of actuator-sensor channels and estimate impact and damage
automatically. Finally, A SHM demonstration system is built on a carbon fiber
composite panel with many bolt holes and stiffeners of an aircraft wing box
based on the damage and impact imaging method, the PSL and the ISS. The
demonstrating results show good performance of the whole SHM system.
Keywords: Structural health monitoring, piezoelectric transducer, time reversal, damage imaging, impact imaging
