RE-EXAMINATION OF NIST ACOUSTIC EMISSION SENSOR CALIBRATION: Part Ⅰ - Modeling the loading from glass capillary fracture

摘要

The procedure for absolute calibration of acoustic emission (AE) sensors is provided in ASTM El 106. In that test method, a glass capillary is fractured against a large steel cylinder in order to generate an acoustic waveform used for calibration of the sensor. In this work the finite element method was used to investigate the viability of the point source load assumption made in the analytic calculation of the resultant waveform for the glass capillary fracture procedure. It was found that the stress field on the steel cylinder due to elastic deformation was not singular, but approximately ellipsoidal in nature. Part II of this work will highlight the impact that the shape of the stress field had on the resultant waveform, leading to the necessity for revision of ASTM El 106.