METHOD OF DIAGNOSING METAL BRIDGE STRUCTURES AND DEVICE FOR IMPLEMENTING SAID METHOD Russian patent published in 2010 - IPC G01N29/14 

FIELD: physics.

SUBSTANCE: signals from acoustic transducers and dynamic deformation from strain sensors are received and recorded. Parametres of acoustic emission signals are evaluated at the moment of loading the metal bridge structure with a passing train. Acoustic signals are digitised and pre-processed. Noise is filtered off and the arrival time of the acoustic signals is recorded and coordinates of developing defects are calculated from the said arrival time. The bridge structure is divided into N zones, in each of which strain sensors and four acoustic transducers, which form a piezoelectric antenna, are fitted. Recording of acoustic emission signals begins at the moment of detecting change in the deformation derivative sign to a positive sign and its overshooting a threshold value and stops at the moment of detecting change in the deformation derivative sign to a positive sign on another strain sensor in that zone. The location of the defect is determined from the difference in arrival time of signals in the piezoelectric antenna picking up the acoustic signals.

EFFECT: faster operation and improved accuracy characteristics with localisation of acoustic emission signals when diagnosing metal bridge structures.

2 cl, 4 dwg