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Angular profile results of torsional type wave modes in an 8-inch schedule 40 steel pipe at different frequencies from transducer arrays with 3 rings, 24 transducers in each ring with a 33-degree gap, including (a) 30 kHz, (b) 40 kHz, (c) 50 kHz, and (d) 60 kHz. , analytical simulations, , FE analysis in ABAQUS. , experimental measurments.
Source publication
Ultrasonic guided wave (GW) inspection is one of the non-destructive testing (NDT) techniques available for the engineering structures. Compared with other NDT techniques, guided waves can propagate a long distance with a relatively high sensitivity to defects in the structure. In order to increase the performance for pipe inspections to meet highe...
Contexts in source publication
Context 1
... experimental measurments. Figure 7 illustrates the distribution of circumferential displacement amplitudes of torsional-type wave modes T(0,1) and F(m,2) at the axial distance 2 m away from the pipe end by using a polar plot. The related results are produced by using analytical simulations, finite element models and experimental measurements. ...
Context 2
... experimental measurments. Figure 7 illustrates the distribution of circumferential displacement amplitudes of torsional-type wave modes T(0,1) and F(m,2) at the axial distance 2 m away from the pipe end by using a polar plot. The related results are produced by using analytical simulations, finite element models and experimental measurements. ...
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Citations
In this paper, elastic wave scattering in hollow pipes with non-axisymmetric and inclined angle defects is studied using finite element (FE) simulations. A comb array transducer is employed in the FE code to excite the pipe in its first longitudinal mode using a 10-cycle sine modulated excitation signal at 120[Formula: see text]kHz central frequency. Defects with variations in geometrical shapes such as depths, axial and circumferential lengths, and inclined angles are investigated to provide detailed analysis of wave propagation patterns and mode conversions in a 12-in diameter pipe. The influence of each geometrical parameter and also possible newborn modes is studied both in time and wavenumber-frequency domain via circumferential order identification approach and dispersion curves. Results show that the depth of a non-axisymmetric circumferential defect has the minimum influence on the propagating mode while crack’s width can influence the measured longitudinal mode in a sinusoidal pattern which is a function of excitation signal’s wavelength. Further, the propagating mode can exhibit higher contribution of either axisymmetric or non-axisymmetric modes based on the reflection patterns, depending on its angle and axial length.
