Circumferential defect detection using ultrasonic guided waves

Abstract

Purpose Quantitatively detecting surface defects in a circular annulus with high levels of accuracy and efficiency has been paid more attention by researchers. The purpose of this study is to investigate the theoretical dispersion equations for circumferential guided waves and then develop an efficient technique for accurate reconstruction of defects in pipes. Design/methodology/approach The methodology applied to determine defects in pipelines includes four steps. First, the theoretical work is carried out by developing the appropriate dispersion equations for circumferential guided waves in a pipe. In this phase, formulations of strain-displacement relations are derived in a general equidistant surface coordinate. Following that, a semi-analytical finite element method (SAFEM) is applied to solve the dispersion equations. Then, the scattered fields in a circular annulus are calculated using the developed hybrid finite element method and simulation results are in accord with the law of conservation of energy. Finally, the quantitative detection of Fourier transform (QDFT) approach is further enhanced to efficiently reconstruct the defects in the circular annuli, which have been widely used for engineering applications. Findings Results obtained from four numerical examples of flaw detection problems demonstrate the correctness of the developed QDFT approach in terms of accuracy and efficiency. Reconstruction of circumferential surface defects using the extended QDFT method can be performed without involving the analytical formulations. Therefore, the streamlined process of inspecting surface defects is well established and this leads to the reduced time in practical engineering tests. Originality/value In this paper, the general dispersion equations for circumferential ultrasonic guided waves have been derived using an equidistant surface coordinate and solved by the SAFEM technique to discover the relationship between wavenumber of a wave and its frequency. To reconstruct defects with high levels of accuracy and efficiency, the QDFT approach has been further enhanced to inspect defects in the annular structure.

Automatic Detection and Classification of Defective Areas on Metal Parts by Using Adaptive Fusion of Faster R-CNN and Shape From Shading

“…Various image processing methods have recently been used for surface defect detection. The autocorrelation method [2], the gray-level co-occurrence matrix [3], the morphological methods [4] and the histogram feature statistics [5] which are used to describe texture properties; Fourier, Gabor and wavelet feature method [6], [7] which finds the textural structure of the image; the fractal body model [8], backscattering model [9] and random field model [10] used to define texture patterns by modeling other features with specific models are image processing methods used for surface defect detection. These traditional methods cannot detect texture defects involving complex textures or any new defect type.…”

Modeling of axisymmetric ultrasonic waves reflected from circumferential cracks in a pipe based on a rigorous analytical theory and implementation on distributed devices

“…Moreau et al [19] introduced the adaptive mesh and surface integral method to enhance FE modelling of wave scattering from a defect, with sophisticated discretization being only applied with respect to the defect plane. The combination of cross-section mesh and axial orthogonal factorization constitutes the so-called semi-analytical finite-element (SAFE) method which has been used in modelling guided waves within railways [20,21], metallic plates [22,23] and pipes [24][25][26]. In another way, the computational cost of three-dimensional FEM can also be reduced by improved discretization.…”

Circumferential thermoelastic Lamb wave in fractional order cylindrical plates

“…Many researchers have studied the propagation characteristics of circumferential guided wave. Da et al [3] derived the dispersion equations of circumferential guided waves propagating along the spiral path of the helix in a hollow cylinder using the SAFEM. Li et al [4] summarized the progress in the detection technology and application of guided waves.…”