An Experimental and Theoretical Comparison of 3D Models for Ultrasonic Non-Destructive Testing of Cracks: Part I, Embedded Cracks

Featured Application The proposed models' validation will enable the proper use of ultrasonic simulation for designing NDT methods for embedded crack detection and characterization. Ultrasonic Non-Destructive Testing (NDT) methods are broadly used for detection and characterization/imaging of cracks. Simulation is of great interest for designing such NDT methods. To model the ultrasonic 3D response of a crack, ultrasonic high frequency asymptotic (semi-analytical) models (such as the Physical Theory of Diffraction-PTD) are known to provide accurate predictions for most classical NDT configurations, and 3D numerical models have also emerged more recently. The aim of this paper is to carry out for the first time an experimental and theoretical comparison of 3D models for ultrasonic NDT of embedded cracks in 3D configurations. Semi-analytical models and a hybrid 3D FEM strategy-combining high-order spectral Finite Elements Method (FEM) for flaw scattering and an asymptotic ray model for beam propagation-have been compared. Both numerical validations and comparisons between simulation and experiments prove the effectiveness of PTD in numerous configurations but validate and demonstrate the improvement provided by the 3D hybrid code, notably for small flaws compared to the wavelength and for shear waves.

Automated summary

This paper proposes a method for designing embedded crack detection and characterization using ultrasonic simulation and compares different 3D models through experimental and theoretical analysis. The results demonstrate the significant improvement of the 3D hybrid code in detecting small flaws and shear waves compared to traditional models.