Study on Lamb Wave Complex Dispersion Relations with out-of-Plane Amplitude Information in Plate Structure

Jintao Liu ； Xin Gu ； Baiqiang Xu

《International Core Journal of Engineering》 9卷5期 (2023/05) Pp. 330-336

https://doi.org/10.6919/ICJE.202305_9(5).0039

摘要

In order to solve the problem that the dispersion curve of the existing plate structure is lack of out‐of‐plane amplitude information, a semi‐analytical method for calculating the complex dispersion curve of the plate structure is proposed in this paper. This method is based on Bloch‐Floquent theory and finite element intrinsic frequency method. By normalizing the maximum displacement of each vibration mode, the dispersion curve in complex wave number domain that can reflect the relative magnitude of out‐of‐plane displacement is obtained. In addition, the dispersion relationship of complex wave number is verified by using finite element software to excite evanescent wave in single mode in frequency domain, and the significance of relative amplitude for the excitation and reception of Lamb wave in practical applications is pointed out.

關鍵字

Non‐destructive Testing ； Finite Element ； Plate Structure ； Bloch‐Floquent Theory ； Finite Element Intrinsic Frequency Method ； Lamb Wave ； Complex Wave Number ； Dispersion Characteristics ； Evanescent Wave

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