Defect reconstruction in a 2D semi-analytical waveguide model via derivative-based optimization

TL;DR

This paper introduces a derivative-based optimization method using the Scaled Boundary Finite Element Method to accurately reconstruct defects like cracks, delaminations, and corrosion in a 2D waveguide during ultrasonic inspection, demonstrating robustness against noise.

Contribution

It presents a novel semi-analytical approach combined with an iteratively regularized Gauss-Newton method for defect reconstruction in waveguides, improving accuracy and efficiency.

Findings

Successful reconstruction of different defect types

Robustness to noisy data demonstrated

Efficient parameterization of defects achieved

Abstract

This paper considers the reconstruction of a defect in a two-dimensional waveguide during non-destructive ultrasonic inspection using a derivative-based optimization approach. The propagation of the mechanical waves is simulated by the Scaled Boundary Finite Element Method (SBFEM) that builds on a semi-analytical approach. The simulated data is then fitted to a given set of data describing the reflection of a defect to be reconstructed. For this purpose, we apply an iteratively regularized Gauss-Newton method in combination with algorithmic differentiation to provide the required derivative information accurately and efficiently. We present numerical results for three different kinds of defects, namely a crack, a delamination, and a corrosion. These examples show that the parameterization of the defect can be reconstructed efficiently and robustly in the presence of noise.