固体中缺陷对声波频谱特性影响的有限元仿真

Finite Element Simulation of the Effect of Defects in Solid on Ultrasonic Spectral Feature

超声检测是无损检测的重要组成部分,其主要检测固体中的缺陷,深入研究超声在固体中的传播机理非常必要,数值仿真在显示了独特的优势。有限元理论已经比较成熟,从其基本原理出发,建立固体中具有吸收边界的二维有限元模型,对含三种典型缺陷:裂纹、方形横穿孔、圆柱形横穿孔的模型进行了仿真研究,由波场快照图清晰的显示了缺陷对超声传播的影响,通过对截取的A-扫描曲线上缺陷和底面回波进行频谱分析,得到不同频域特征量和缺陷敏感频率可以识别各种缺陷。仿真结果对实际应用有参考意义。

Ultrasonic testing is an important part of NDT, and it mainly examines the defects in solid. It is necessary to study the mechanism of ultrasonic propagation in solid, and numerical simulation shows particular advantage in this field. Based on the principle of finite element method, a two -dimensional finite element model can be developed for solid. The model involves three typical defects： crack, traverse square cavity, traverse cylindrical cavity, and they are studied by simulation. The snapshots display the effect of defects on ultrasonic propagation. The simulation result will be referential to the practical application.