Experimental Research on Damage Detection in Beams by Using Shear Horizontal Guided Waves Based on Time Reversal Method

The fundamental shear horizontal mode SH0 was used for beam detection and time reversal method was applied to signal reconstruction.Under the condition of the notch with different depths, damage index(DI)was calculated and used to characterize damage levels of beam structures.In the experiment, thickness-shear piezoelectric transducers were used for the excitation and reception of SH0 mode and the notch with different depths was detected.Captured signals were time-reversed and reconstruction signal was obtained.Damage index can be calculated by the comparison between reconstruction signals and excitation signal.The result showed the value of DI increased monotonically with the increase of damage depth.The research demonstrats there is a certain potential to detect defects in beams by using shear horizontal guided wave method based on time reversal method.