Session: 14 - 01 Ultrasonic Arrays I

Paper Number: 108670

108670 - Ultrasonic Crack-Like Defect Characterization Using Advanced Beamforming Techniques 

Crack-like defect detection and characterization is an important challenge in several industries such as nuclear or aeronautics. Ultrasonic testing is often used in on-site inspections, mostly with phased array probes. Standard beamforming methods, such as standard hardware focusing or the Total Focusing Method, are using the Delay-And-Sum (DAS) method to reconstruct images. Nevertheless, they often suffer from poor resolution and low Signal to Noise Ratio (SNR). This is even intensified when the inspection is performed on coarse-grained materials such as some stainless steel parts in nuclear industry. In this study, we propose to use several advanced beamforming techniques to improve crack-like detection and characterization. First, coherence-based techniques such as Phase Coherence Imaging (PCI) are assessed. They take advantage of different coherence computations (based on phase or amplitude) and enhance diffraction responses that are generally used for crack identification. Second, inverse methods that we recently proposed are assessed in this context. These methods generally improve resolution and SNR, even in coarse-grained materials. In this work, experimental tests have been performed from stainless steel samples containing crack-like defects with various heights. We show that coherence-based beamformers are effective to detect tip echoes from cracks which is a good tool for sizing. Inverse methods are efficient to resolve different diffraction points from a crack.

Presenting Author: Ewen Carcreff The Phased Array Company

Presenting Author Biography: ...