兰姆波在薄钢板无损检测中的应用研究

Experimental Study for Nondestructive Testing of Steel Sheet by Lamb Waves

摘要: 通过在钢板上钻制直径不等的孔来模拟钢板中的孔洞类缺陷，采用线切割加工出不同深度的狭缝来模拟钢板中的分层缺陷。采用一发一收法，分别在两种厚度的钢板上激励出兰姆波进行检测，通过对比分析检测到的缺陷前后板中兰姆波信号，采用时频分析方法识别出板中激发的兰姆波模式以及模态转换现象，初步确定特定缺陷形态对兰姆波在板中传播的影响。

Abstract: The holes with different diameter were drilled in the steel sheet to simulate the hole-class defects, and slots with different depth were cut by WEDM in the steel sheet to simulate the lamination defects. The two types of plates were detected by pitch-catch technique with Lamb waves respectively. Signals which were detected in the defect-free plate and plate with defect were compared. Time-frequency analysis was employed to recognize the Lamb wave modes and mode conversion, and some effect of the given defects on Lamb waves in the steel sheet is determined primarily.