An elastodynami`c hybrid boundary element study for elastic guided wave interactions with a surface breaking defect
An elastodynami`c hybrid boundary element study for elastic guided wave interactions with a surface breaking defect
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DOI：
10.1016/s0020-7683(99)00142-0
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发表时间：
2000-07
影响因子：
3.6
通讯作者：
Younho Cho;J. Rose
中科院分区：
文献类型：
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作者：
Younho Cho;J. Rose
利用混合边界元方法(BEM)结合弹性动力学边界积分方程和兰姆波简正波展开技术，研究了弹性导波与各种缺陷相互作用的可能性。基于能量守恒和导波散射问题的现有基准数据，验证了边界元程序的准确性。通过对任意形状缺陷的二维(2-D)参数研究，从表面破裂裂纹模型到圆形表面缺陷，局部地选择包含缺陷的波导横截面作为给定入射模式、频率和一组特定材料特性的模型。通过数值计算模式的反射系数和透射率来评估模式的灵敏度，并获得潜在的良好分类特征。结果表明，导波散射分布随入射模式、频率、缺陷形状和尺寸的变化表现出不同的特性，为缺陷分类和尺寸分析提供了足够丰富的特征提取信息。理论分析可以用来为模式识别分析研究中的数据采集和特征选择建立有效的指导方针。文中给出了实例计算结果。
Elastic guided wave interactions with various defects are explored for investigating defect characterization possibilities by using a hybrid boundary element method (BEM) in combination with an elastodynamic boundary integral equation and the Lamb wave normal mode expansion technique. The BEM code accuracy is verified based on energy conservation and available bench marking data for guided wave scattering problems. Through two-dimensional (2-D) parametric studies for an arbitrarily shaped defect, from a surface breaking crack model to a round surface defect, a waveguide cross-section including a defect is locally selected as a model for a given incident mode, frequency and a specific set of material properties. Mode reflection and transmission factors are numerically calculated to evaluate mode sensitivities and to obtain the potentially good classification features. It turns out that the guided wave scattering profiles show quite different behaviors as functions of incident mode, frequency, defect shape and size in providing us with enough rich feature extraction information for defect classification and sizing analysis. The theoretical analysis can be used to establish efficient guidelines for both data acquisition and feature selection in a pattern recognition analysis program of study. Sample results are presented.