Affiliations: School of Aeronautics, Northwestern Polytechnical
University, Xi'an, Shaanxi, China | Department of Mechanical and Aerospace Engineering,
North Carolina State University, Raleigh, NC, USA
Note: [] Corresponding author: Fuh-Gwo Yuan, Department of Mechanical and
Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA.
Tel.: +1 919 515 5947; Fax: +1 919 515 7968; E-mail: [email protected]
Abstract: This paper presents a detailed study on the impact source
identification of a plate structure using time-reversal (T-R) method. Prior to
impact monitoring, the plate is calibrated (or characterized) by transfer
functions at discrete locations on the plate surface. Both impact location and
impact loading time-history are identified using T-R technique and associated
signal processing algorithms. Numerical verification for finite-size isotropic
plates under low velocity impacts is performed to demonstrate the versatility
of T-R method for impact source identification. The tradeoff between accuracy
of the impact location detection and calibration spacing is studied in detail.
In particular, the effect of plate thickness on calibration spacing has been
examined. A number of parameters selected for determining the impact location,
approximated transfer functions and steps taken for reconstructing the impact
loading time-history are also examined. Two types of noise with various
intensities contaminated in strain response and/or transfer functions are
investigated for demonstrating the stability and reliability of the T-R method.
The results show that T-R method is robust against noise in impact location
detection and force reconstruction in circumventing the inherent
ill-conditioned inverse problem. Only transfer functions are needed to be
calibrated and four sensors are requested in T-R method for impact
identification.
