Basic Principles of Ultrasonic Time Reversal Processing in Non-Destructive Testing

摘要: Ultrasonic non destructive testing needs large focusing apertures in order to detect small defects solid media. Current ultrasonic inspections use scanned immersion techniques. In recent years, two different approaches have been extensively studied obtain focused beams through non-planar liquid-solid interfaces. The first technique uses one or several transducers whose geometry is matched the interface and desired focal point. second based on combination of a multi-elements array set electronic delay lines values are produce focusing. These techniques suffer from important limitations. They an exact priori knowledge require highly precise positioning defect.