Ultrasound simulation for 3D-axisymmetric models

Development of ultrasound nondestructive evaluation testing (NDT) techniques has involved a combination of both analytic and experimental methods. In contrast, relatively little software exists for ultrasound simulation in NDT, particularly in comparison to that existing for stress-strain and electromagnetic areas. This paper describes new software for simulating the full (longitudinal and shear) solution to the three-dimensional (3D) axisymmetric wave equation. The simulation software is able to model both liquids and solids, and also accounts for losses using a classic viscoelastic model. The program computes the solution using a finite difference time domain algorithm, and evaluates the displacement vector at each (discrete grid) point of the object. Sources and receivers may be placed anywhere in or on the object, which is assumed to be cylindrical. A comparison of the on-axis diffraction pattern results obtained with the simulation software show excellent agreement with analytic results. Results using a cladded rod are also presented. This software should help to broaden the use of computational methods in ultrasonic NDT and in ultrasonics in general.