Impact localising method using an acoustic emission monitoring system, in particular for pressure-retaining boundaries in power plants

摘要

With regard to the rates of propagation of burst signal components detected by sensors for structure-borne sound, it has so far been necessary to rely on suppositions when using monitoring systems for structure-borne sound. The invention is intended to specify an exact method of determining the rates of propagation and the burst location. …??Starting from the realisation that the frequency spectrum of the particular burst includes the information for clarifying the dispersion behaviour, identifying the soundwave modes and deriving the group velocity of these modes, a determination is made of differences in burst signal propagation times, of wave modes, in particular s0 and a0 modes, and of the associated group velocities, and it is possible on the basis of the general relationship LS-E = ti,n . Vi . Vn/(Vi -Vn) for the sound path from the burst location up to the sensors for structure-borne sound to be determined in a doubly redundant fashion owing to the fact that at least three burst signal components are separated by appropriate electronic signal filter systems. …??Monitoring systems for structure-borne sound, in particular for nuclear power stations. …IMAGE…