Method and Apparatus for Examining Structures Using Stimulated Acoustic Emission

摘要

A vibrator is held in contact with a structure undergoing testing, such as an airplane wing. Vibrations are distributed through the structure and structural defects such as fissures will respond by emitting an acoustical signal. The acoustic signal may occur over a wide frequency range. A pick-up having a crystal transducer also makes contact with the surface of the structure to detect acoustic emissions. The crystal has a wide band response capable of detecting structural defect acoustic emissions. The pick-up has electrical leads connected thereto so that the acoustic emissions are converted to electrical signals which may be recorded or viewed on an oscilloscope. Movement of the pick-up across the surface of the structure will help determine the location of the structural defect. (Author)