Predicting AE attenuation in structures by geometric analysis

Predicting acoustic emission attenuation in small steel blocks using a ray tracing technique

“…Since the AE must travel from the source to the sensor, the ability to detect a given source decreases with the distance between the source and the transducer [1][2][3][4][5] . AE Attenuation can result from a range of processes, such as scattering, spreading, absorption and dispersion.…”

“…A programme has been developed in C++, using the ACIS 3D solid modelling kernel and a rendering programme (HOOPS) [15] , to create the necessary algorithms and graphical user interface (GUI) for AE ray tracing. The new programme uses the basic internal ray simulation methodology developed by Lim et al [4] , adapted to give more accurate and stable results for the simulation of the internal rays and extended to simulate surface rays and combinations of internal and surface rays. Figure 1 shows the overall programme flow chart, which can be summarised in five main steps, as seen in Figure 2: source generation, filtering, path generation, sensor representation and data recording.…”

“…Although these approaches provide accurate solutions, they are computationally expensive, complex in implementation for all but the simplest geometries and wave modes and, in some cases, are restricted, for example to single wave modes or to low frequencies [4] .…”

“…The current work follows on from a novel approach to ray tracing first suggested by Lim et al, in which they showed that generating rays in a 3D solid model can be used to assess the attenuation in engineering structures almost without limit of geometric complexity [4] . At this stage, a series of simple steel shapes of relatively small dimensions are simulated with the total reflection of rays in order that the results can be matched to some experimental observations, which have also been made as part of the work.…”

Aspects of acoustic emission attenuation in steel pipes subject to different internal and external environments

“…The attenuation, and particularly the effects of interfaces, can also be examined by imagining the energy to be moving along sound rays (Fig. 17), losing energy at each reflection according to an absorption coefficient of the surface, and reflecting according to Snell's law [15,16].…”