Damage Identification in Composites Based on Hilbert Energy Spectrum and Lamb Wave Tomography Algorithm

Lamb wave has already been known as one of the most prominent and promising tools in the field of nondestructive testing due to its wide range in detection and high sensitivity to damages. This paper put forward a method for damage location imaging on the basis of Hilbert Energy Spectrum and Lamb Wave Tomography. The damage localization imaging of composites were realized by simulation and experiment respectively. Firstly, the characteristics possessed by propagation of Lamb Wave before and after damages of composite plate were analyzed through the employment of simulation. The array of circular sensor was evenly arranged on the composite plate selected, and the each sensor acts as an actuator in turn for the purpose of generating Lamb Wave. In addition, other sensors were responsible for the collection of response signal. Finally, the damage factor was determined by the calculation on the difference between signals with or without damage by using Hilbert Energy Spectrum, and the location imaging of damage was achieved by adopting the probability imaging algorithm. It was shown by the experimental results that the maximum errors for imaging location of single damage and multiple damages were 5.00 mm and 9.22 mm, respectively. This method adopted avoids the extraction process of complex reflection signal, and thus it has great potential in damage location and identification conducted for composite materials.