METHOD FOR NON-DESTRUCTIVE INVESTIGATION OF THE BOTTOM OF METALLIC TANK STRUCTURES

摘要

The present invention relates to a method for non-destructive investigation of the bottom of metallic tank structures, comprising the following steps: a) positioning an acoustic sensor at a point of contact between the tank wall and the bottom; b) submitting the structure to induced acoustic emission signals caused by a source of energy in close proximity with the position of the acoustic sensor; c) collecting data by the sensor and recording it; d) moving to a different position at an interval of 0.1 - 1.0 m along the perimeter of the tank bottom; e) repeating steps a) - d) until the entire perimeter of the bottom of the tank is investigated; f) determining the position and amplitude of all the defects, by considering the physical - mechanical features of the metal, the geometry of the tank, the propagation time of the backscattered signals determined by the defects and the amplitude of deviations of emission frequencies; f) performing the spectral analysis and data interpretation by considering the physical - mechanical features of the metal, the features of the induced acoustic emission signals, in particular the shift of the resonance frequencies of induced acoustic emission signals against the etalon values of frequencies of the intact metal and against etalon values specific for different types of degradation processes.