TFM imaging simulations of defects near or in the weld bevel: modelling approach and customized finite element tools

Abstract

In safety-critical industries, including the nuclear sector, ultrasonic testing (UT) of welded components is an area of continuous improvement. We have collaborated on developing advanced UT simulation tools to address challenges in monitoring and imaging defects near or within a weld bevel. These tools, integrated into the CIVA software platform, use hybrid approaches combining ray models and finite elements (FE) to accurately simulate wave propagation and diffraction phenomena in both 2D and 3D inspection configurations. While computation time is longer compared to ray-based approaches, the results serve as a reference for improving reliability and validating simulation tools. A comprehensive parameterization of the weld is proposed, utilizing knowledge on anisotropy, attenuation properties, and variations within the bevel, to achieve reliable UT results. This paper reviews the new features developed, including the integration of the MINA model for the weld description and improvements in bevel geometry. The automated coupling methodology and meshing procedures, which do not require any specific numerical expertise to be used, are discussed. As an application, we present TFM imaging simulations, comparing results from the standard paraxial ray-based approach with the new module utilizing the FE computational core.