通过PZT(锆钛酸铅)晶片激励和接收超声S0导波信号,对人工腐蚀缺陷进行检测,建立三维实体有限元模型,研究锥形深度剖面腐蚀缺陷与超声导波相互作用机理,分析不同腐蚀深度、剖面倾角及直径对导波信号的影响。结果表明: 超声导波与腐蚀缺陷相互作用时伴随着反射和透射,发生波型转换;反射系数和散射系数在一定范围内随腐蚀缺陷深度的加深而明显增大,随腐蚀缺陷剖面倾角的增加而逐渐增大,随腐蚀缺陷直径的变化呈周期性变化;腐蚀缺陷深度较其剖面倾角和直径对导波信号更敏感。

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 3D finite 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.