Detection of Corrosion Defects in Plate by S_0 Guided Wave

Corrosions are quite common in large industrial platy structures of ships,aircraft,petrochemical storage tanks and so on.When the corrosions are severe to a certain extent,they will undermine the safe use of structures,so detecting corrosion defects in plate shows importance in engineering applications.Corrosion defects in aluminum alloy plate were inspected by S0 guided wave which was excited and received by PZT wafers.The 3Dfinite element models were constructed to analyze the interaction between S0 guided wave and the tapered depth profile corrosions.The parameter studies are including the inclination angle of tapered profile,the depth and the diameter of corrosion.The results indicat that in the process of interaction,wave mode conversion occurs with reflection and transmission.The coefficients of reflection and transmission increase with the depth of corrosion and the inclination angle of tapered profile.Furthermore,the coefficients show periodic changes with corrosion diameters.Among the three parameters,the depth of corrosion is the most sensitive to signals.