Defect Imaging for Plate-like Structures Using Diffuse Acoustic Wave Generated by Modulated Laser

摘要

Authors have studied defect imaging technique for plate-like structures, which creates an image beyond diffraction limit and can be applied to a plate-like structure with a complex shape because this technique just uses variations of flexural vibration energy due to the differences in nominal bending stiffness at laser spots. However, this technique generates spurious images caused by the resonance as well as defect images. The current study described how the spurious images can be reduced using diffuse acoustic wave, and then showed that images of defects and adhesive regions can be obtained appropriately even in such complex structures as a flat plate with a complex shape, a curved plate, and a branch pipe.