基于时间－空间变换的超声导波检测新技术研究-工程力学.PDFVIP

第22 卷第5 期 工 程 力 学 Vol.22 No.5 2005 年 10 月 ENGINEERING MECHANICS Oct. 2005 文章编号：1000-4750(2005)05-0089-05 基于时间－空间变换的超声导波检测新技术研究 *焦敬品，何存富，吴 斌，费仁元，王秀彦 (北京工业大学机电学院，北京 100022) 摘 要：超声导波的频散和多模态特性，对超声导波检测的效果和检测范围有很大的影响。在分析超声导波时间 －空间传播特性基础上，建立了超声导波检测的空间表述模型。由于考虑了导波传播过程中的频散特性，空间表 述模型减小了频散对导波检测波形的影响，提高了检测系统分辨率，并可以直接获得结构中特征体信息，如端面、 缺陷的位置等。实验结果表明，该技术可以大大提高超声导波检测范围和检测效果。 关键词：无损检测；超声导波；时间-空间变换；频散；信号处理 中图分类号：TG115.28 文献标识码：A A NEW TECHNIQUE OF GUIDED WAVES FOR NON-DESTRUCTIVE TESTING METHODS BASED ON TIME -SPACE TRANSFORM * JIAO Jing-pin , HE Cun-fu , WU Bin , FEI Ren-yuan , WANG Xiu-yan (Beijing University of Technology, Beijing 100022, China) Abstract: Guided waves have been utilized in various manners for non-destructive evaluation and testing. Due to the dispersive and multi-mode characteristics of guided waves, the pulse of energy will spread out in space and time as it propagates. For long-range guided waves inspection application, it constrains the choice of operating point to regions on the dispersion curves where dispersion effect is relatively small. Based on the knowledge of the guided waves propagation in time-space, a space model is established to compensate the dispersion in long range guided wave testing. Consequently, the characteristics of structure, such as the length of structure or the position of defect, can be obtained directly, and the resolution of detection can be improved. It is shown that the technique can improve and extend the effect of guided waves for NDT methods. Key words: NDT; guided waves; time-space transform; dispersion; signal processing 与常规无损检测技术相比，超声导波技术具有 征信息检测，如胶接接头、扩散连结或复合材料等 更快捷、更灵敏、更经济的特点，已广泛应用于多