Numerical Simulation on Detecting Defects in Pipes Using T(0,1) Mode Guided Wave

2013 ◽  
Vol 823 ◽  
pp. 456-460 ◽  
Author(s):  
Long Xiang Zhu ◽  
Yue Min Wang ◽  
Feng Rui Sun
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Guided Waves ◽  
Guided Wave ◽  
Experimental Result ◽  
Propagation Property ◽  
Wave Technology ◽  
Pipe Model ◽  
3D Solid

The guided-wave technology is very efficient in inspecting a large portion of pipe. In order to study the propagation property of guided wave in pipe and the interaction between guided waves and defects, pipe model was established using 3D solid finite element in the software ANSYS. Tangential displacements were prescribed on the nodes in the pipe end and the propagating of T(0,1) mode guided wave in pipes was simulated. The detecting signals for the pipe model with different defects were extracted, which matched very well with experimental result.

Method to Detect Bolting Devices Based on Ultrasonic Guided Wave

2012 ◽  
Vol 226-228 ◽  
pp. 1906-1909
Author(s):  
Min Hui Xu ◽  
Qiao Qian Lan ◽  
Wei Jian Jin
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Theoretical Analysis ◽  
Guided Waves ◽  
Test System ◽  
Guided Wave ◽  
Effective Length ◽  
Engineering Practice ◽  
Ultrasonic Guided Wave

Bolting devices is very popular in industrial application, this paper presents a new solution aimed at the problem faced in detecting the construction quality. The solution is based on the engineering practice, and we introduce Ultrasonic Guided Wave NDT technology in the detecting process. Under laboratory conditions, Longitudinal Guided Waves are used in detecting the bolting devices, the experimental results are consistent with the theoretical analysis. At the same time, finite element method is applied into the Numerical Simulation of the propagation of Longitudinal Guided Waves in bolts, thus a test system utilized in detecting the effective length and defects of bolts developed.

scholarly journals Longitudinal Guided Wave Inspection of Small-Diameter Elbowed Steel Tubes with a Novel Squirrel-Cage Magnetostrictive Sensor

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Yao Liu ◽  
Xiucheng Liu ◽  
Chehua Yang ◽  
Wenxin Guo ◽  
Bin Wu ◽  
...  
Keyword(s):  
Finite Element ◽  
Guided Waves ◽  
Mode Conversion ◽  
Small Diameter ◽  
Longitudinal Mode ◽  
Guided Wave ◽  
Wall Defect ◽  
Squirrel Cage ◽  
Simulation Results ◽  
Magnetostrictive Sensor

In the study, ultrasonic longitudinal mode guided waves were employed to detect defects in elbowed tubes (without welds) with a diameter of 10 mm. Finite element simulation results highlighted that the emitted L(0,1) mode guided waves experienced strong reflection and mode conversion at the elbow region to generate F(1,1) mode, followed by slow and weak F(2,1) mode. The guided wave reflected from the elbow with a through-wall defect was manifested as two overlapped wave packets, which were good indicators of a defective elbow. To conduct L(0,1) mode guided waves inspection on the small-diameter elbowed tubes, a novel tailored squirrel-cage magnetostrictive sensor was employed in the experiment. The new sensor employed the configuration of segmental iron-cobalt strips and small-size permanent magnet arrays. The entire sensor is composed of two identical C-shaped sensor elements and can be recycled and installed conveniently. Experimental results obtained from healthy and defective tubes were consistent with the conclusions obtained from finite element simulations. An artificial through-wall defect at the elbow and a notch defect at the straight part of the tube could be simultaneously detected by L(0,1) mode guided waves through comparing experimental signals with simulation results.

Guided Wave Focusing Mechanics in Pipe

2003 ◽  
Author(s):  
Takahiro Hayashi ◽  
Koichiro Kawashima ◽  
Zongqi Sun ◽  
Joseph L. Rose
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Wave Structure ◽  
Guided Wave ◽  
Pipe Inspection ◽  
Specific Point ◽  
Wave Focusing ◽  
Beam Focusing ◽  
Subsequent Time

Guided waves can be used in pipe inspection over long distances. Presented in this paper is a beam focusing technique to improve the S/N ratio of the reflection from a tiny defect. Focusing is accomplished by using non-axisymmetric waveforms and subsequent time delayed superposition at a specific point in a pipe. A semi-analytical finite element method is used to present wave structure in the pipe. Focusing potential is also studied with various modes and frequencies.

Contribution of Lamb wave modes in the formation of higher order modes cluster (HOMC) guided waves

2021 ◽  
pp. 095440622110424
Author(s):  
Z Abbasi ◽  
F Honarvar
Keyword(s):  
Finite Element ◽  
Wave Packet ◽  
Lamb Wave ◽  
Guided Waves ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Cross Sectional ◽  
Higher Order Modes ◽  
Wave Modes

In recent years, Higher Order Modes Cluster (HOMC) guided waves have been considered for ultrasonic testing of plates and pipes. HOMC guided waves consist of higher order Lamb wave modes that travel together as a single nondispersive wave packet. The objective of this paper is to investigate the effect of frequency-thickness value on the contribution of Lamb wave modes in an HOMC guided wave. This is an important issue that has not been thoroughly investigated before. The contribution of each Lamb wave mode in an HOMC guided wave is studied by using a two-dimensional finite element model. The level of contribution of various Lamb wave modes to the wave cluster is verified by using a 2D FFT analysis. The results show that by increasing the frequency-thickness value, the order of contributing modes in the HOMC wave packet increases. The number of modes that comprise a cluster also increases up to a specific frequency-thickness value and then it starts to decrease. Plotting of the cross-sectional displacement patterns along the HOMC guided wave paths confirms the shifting of dominant modes from lower to higher order modes with increase of frequency-thickness value. Experimental measurements conducted on a mild steel plate are used to verify the finite element simulations. The experimental results are found to be in good agreement with simulations and confirm the changes observed in the level of contribution of Lamb wave modes in a wave cluster by changing the frequency-thickness value.

CALCULATION OF DISPERSION CURVES FOR ARBITRARY WAVEGUIDES USING FINITE ELEMENT METHOD

2014 ◽  
Vol 06 (05) ◽  
pp. 1450059 ◽  
Author(s):  
KAIGE ZHU ◽  
DAINING FANG
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Dispersion Curves ◽  
Guided Wave ◽  
Sandwich Plates ◽  
Multilayered Structures ◽  
Finite Element Software ◽  
Honeycomb Sandwich ◽  
Element Method

Dispersion curves for waveguide structures are an important prerequisite for the implementation of guided wave-based nondestructive evaluation (NDE) approach. Although many methods exist, each method is only applicable to a certain type of structures, and also requires complex programming. A Bloch theorem-based finite element method (FEM) is proposed to obtain dispersion curves for arbitrary waveguides using commercial finite element software in this paper Dispersion curves can be obtained for a variety of structures, such as homogeneous plates, multilayered structures, finite cross section rods and honeycomb sandwiches. The propagation of guided waves in honeycomb sandwich plates and beams are discussed in detail. Then, dispersion curves for honeycomb sandwich beams are verified by experiments.

Finite-element simulations of Stoneley guided-wave reflection and scattering at the tips of fluid-filled fractures

Geophysics ◽  
2010 ◽  
Vol 75 (2) ◽  
pp. T23-T36 ◽  
Author(s):  
Marcel Frehner ◽  
Stefan M. Schmalholz
Keyword(s):  
Finite Element ◽  
Elastic Body ◽  
Deformation Behavior ◽  
Guided Waves ◽  
Amplitude Ratio ◽  
Crack Tip ◽  
Two Dimensions ◽  
Guided Wave ◽  
Body Waves ◽  
Crack Geometry

The reflection and scattering of Stoneley guided waves at the tip of a crack filled with a viscous fluid was studied numerically in two dimensions using the finite-element method. The rock surrounding the crack is fully elastic and the fluid filling the crack is elastic in its bulk deformation behavior and viscous in its shear deformation behavior. The crack geometry, especially the crack tip, is resolved in detail by the unstructured finite-element mesh. At the tip of the crack, the Stoneley guided wave is reflected. The amplitude ratio between reflected and incident Stoneley guided wave is calculated from numerical simulations, which provide values ranging between 43% and close to 100% depending on the type of fluid filling the crack (water, oil or hydrocarbon gas), the crack geometry (elliptical or rectangular), and the presence of asmall gas cap at the cracktip. The interference of incident and reflected Stoneley guided waves leads to a node (zero amplitude) at the tip of the crack. At other positions along the crack, this interference increases the amplitude. However, the exponential decay away from the crack makes the Stoneley guided wave difficult to detect at a relatively short distance away from the crack. The part of the Stoneley guided wave that is not reflected is scattered at the crack tip and emitted into the surrounding elastic rock as body waves. For fully saturated cracks, the radiation pattern of these elastic body waves points in every direction from the crack tip. The emitted elastic body waves can allow the detection of Stoneley guided wave-related resonant signals at distances away from the crack where the amplitude of the Stoneley guided wave itself is too small to be detected.

Plastic Crushing Behavior of Thin-Walled Spheres

2008 ◽  
Vol 33-37 ◽  
pp. 719-724
Author(s):  
P. Xue ◽  
J.P. He ◽  
Yu Long Li
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Deformation Process ◽  
Experimental Result ◽  
Plastic Deformation Process ◽  
Post Buckling ◽  
Thin Walled ◽  
Crushing Behavior

Plastic crushing behavior of thin-walled spheres under various loading cases is studied using Finite Element Method. The entire plastic deformation process is tracked during the post-buckling process. The results are compared with the experimental results reported in literature [13], and very good agreements between the numerical simulation and the experimental result are achieved.

Guided Wave Focusing Mechanics in Pipe

2005 ◽  
Vol 127 (3) ◽  
pp. 317-321 ◽  
Author(s):  
Takahiro Hayashi ◽  
Koichiro Kawashima ◽  
Zongqi Sun ◽  
Joseph L. Rose
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Wave Structure ◽  
Guided Wave ◽  
Pipe Inspection ◽  
Specific Point ◽  
Wave Focusing ◽  
Beam Focusing ◽  
Subsequent Time

Guided waves can be used in pipe inspection over long distances. Presented in this paper is a beam focusing technique to improve the S∕N ratio of the reflection from a tiny defect. Focusing is accomplished by using nonaxisymmetric waveforms and subsequent time delayed superposition at a specific point in a pipe. A semianalytical finite element method is used to present wave structure in the pipe. Focusing potential is also studied with various modes and frequencies.

Multiple Crack Detection of Pipes Using PZT-Based Guided Waves

2013 ◽  
Vol 448-453 ◽  
pp. 3702-3708 ◽  
Author(s):  
Shi Yan ◽  
Ji Qi ◽  
Nai Zhi Zhao ◽  
Yang Cheng ◽  
Sheng Wen Jun Qi
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Crack Detection ◽  
Guided Waves ◽  
Arrival Time ◽  
Ultrasonic Guided Waves ◽  
Multiple Crack ◽  
Finite Element Software ◽  
Reflected Signal

This paper focuses on the multiple crack detection of steel pipelines using PZT-based guided waves. Numerical simulations of cracked pipes based on ultrasonic guided-waves are conducted by using the ANSYS finite element software. Based on the analysis of the reflected signal, the arrival time of the crack reflection waves are determined and the crack positions are accurately evaluated by the calculation of the travel time and group velocity of the PZT-based guided waves. The crack parameters are numerically altered to determine how the parameters impact the sensitive degree of the pipe crack damage. To validate the efficiency of the numerical simulation, an experiment of the multiple crack detection for the same parameter pipe with the numerical model is performed in the laboratory, and the results match well with the numerical simulation.

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