This study presents a new impact localization technique that can pinpoint the location of an impact event within a
complex aircraft fuselage using a time reversal concept and a scanning laser Doppler vibrometer (SLDV). First, an
impulse response function (IRF) between an impact location and a sensing piezoelectric transducer is approximated by
exciting the sensing piezoelectric transducer instead and measuring the response at the impact location using SLDV.
Then, training IRFs are assembled by repeating this process for various potential impact locations and sensing
piezoelectric transducers. Once an actual impact event occurs, the impact response is recorded and compared with the
training IRFs. The correlations between the impact response and the IRFs in the training data are computed using a
unique concept of time reversal. Finally, the training IRF, which gives the maximum correlation, is chosen from the
training data set, and the impact location is identified. The proposed impact technique has the following advantages over
the existing techniques: (1) it can be applied to isotropic/anisotropic plate structures with additional complex features
such as stringers, stiffeners, spars and rivet connections; (2) only simple correlation calculation based on unique time
reversal is required, making it attractive for real-time automated monitoring; (3) temperature variation barely affects the
localization performance; and, (4) training is conducted using non-contact SLDV and the existing piezoelectric
transducers which may already be installed for other structural health monitoring purposes. Impact events on an actual
aluminum fuselage specimen are successfully identified using the proposed technique.