Probability based impact localization in plate structures using an error index

Abstract This study presents a Probability based Impact Localization (PIL) method for plate structures. To this aim, an Error Index (EI) is introduced based on the Time of Arrivals (TOAs) of impact induced flexural waves. Due to dispersive characteristic of flexural waves and also presence of noise in real practices, the exact determination of TOAs is complicated and requires the interpretation of signals. This limits the application of impact localization methods for active systems. To overcome this obstacle, a novel TOA prediction method is developed based on the energy of signals till different times. The proposed PIL method has the following advantages: (a) it can be applied to isotropic/anisotropic plate structures; (b) it doesn’t require any signal interpretation, making it attractive for active impact monitoring systems; (c) for anisotropic materials it doesn’t require the accurate knowledge of the wave velocity in all directions of propagation; (d) it doesn’t need a reference database; and (e) it remains effective even in the presence of noise. The accuracy of the proposed PIL method is experimentally assessed by dropping a steel ball on a carbon fibre composite plate with existing piezoelectric transducers that can also be used for other structural health monitoring applications. It is shown that the proposed PIL method is able to highlight impact location on different regions of composite plate even when 20% of sensors are damaged and receive false signals.