Solodov Igor, Kreutzbruck Marc
Institute for Polymer Testing (IKT), University of Stuttgart, 70569 Stuttgart, Germany.
Institute for Polymer Testing (IKT), University of Stuttgart, 70569 Stuttgart, Germany.
Ultrasonics. 2020 Dec;108:106221. doi: 10.1016/j.ultras.2020.106221. Epub 2020 Jul 6.
A new approach to nonlinear frequency mixing based on local damage resonance is proposed, analysed and tested experimentally for flexural waves in composites. The method is free from stringent requirements on the mode types and frequencies for interacting waves. The resonance of damage enhances strongly its higher-order nonlinear response and boosts the efficiency of generation for numerous-order combination frequencies. The damage resonance combined with its strong nonlinearity also provides locality of nonlinear interaction even for continuous wave operation. The combination frequencies generated locally in the damaged area are the footprints of damage and used for its detection, location and visualization. A single C-scan yields a number of images of the defect corresponding to various nonlinearly generated frequencies. Various versions of the resonant frequency mixing are considered and applied to nonlinear imaging of defects in composite materials.
提出了一种基于局部损伤共振的复合材料弯曲波非线性频率混合新方法，并进行了分析和实验测试。该方法对相互作用波的模式类型和频率没有严格要求。损伤共振极大地增强了其高阶非线性响应，并提高了多阶组合频率的产生效率。损伤共振及其强非线性特性即使在连续波操作下也能提供非线性相互作用的局部性。在损伤区域局部产生的组合频率是损伤的特征，可用于损伤检测、定位和可视化。一次C扫描可生成对应于各种非线性产生频率的多个缺陷图像。考虑了共振频率混合的各种形式，并将其应用于复合材料缺陷的非线性成像。
