Modelling the scattering of ultrasonic signals from 3D rough surfaces using the distributed point source method (DPSM)

摘要

In corrosion mapping applications many thousands of ultrasonic signals from complex surfaces are acquired. Analysis of the statistics of the distributions is valuable to get an insight into the wall loss mechanisms. In order to compare experimental data to simulated results a very fast model is required as many thousands of simulations need to be carried out. This paper presents a simulation approach based on the distributed point source method (DPSM). The DPSM is a mesh free semi-analytical technique for computing ultrasonic fields and signals. It produces results of a similar accuracy to finite element methods (FEM), in significantly less time: usually an order of magnitude. The DPSM was then applied to calculate the statistical distribution of wall thickness measurements, as would be acquired in corrosion mapping applications. The results are presented and it is discussed how the timing algorithms and the actual surface topology affect the ultrasonically measured thickness.