Reflection and Mode Conversion of Fundamental Torsional Guided Wave Mode From Lack of Bonding in Induction Pressure Welding

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Deepesh Vimalan ◽  
Krishnan Balasubramaniam ◽  
Prabhu Rajagopal
Keyword(s):  
Mode Conversion ◽  
Three Dimensional ◽  
Wave Mode ◽  
Bond Line ◽  
Fe Analysis ◽  
Guided Wave ◽  
Pressure Welding ◽  
Cross Sectional ◽  
3D Finite Element ◽  
Guided Mode

Interaction of fundamental torsional ultrasonic pipe guided mode T(0, 1) from defects caused by induction pressure welding (IPW) process is studied using three-dimensional (3D) finite element (FE) analysis validated by experiments. Defects are assumed as cross-sectional notches along the weld bond-line, and both surface-breaking and embedded features are considered. Results show that T(0, 1) mode reflection from weld defects is strongly influenced by features of the weld itself. However, with supplementary results such as the mode-converted flexural F(1, 3) and F(1, 2) modes and circumferential variation of T(0, 1) reflection, there is potential for an effective screening solution.

Pavement Damage Due to Conventional and New Generation of Wide-Base Super Single Tires

2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh
Keyword(s):  
Carrying Capacity ◽  
Material Properties ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Load Carrying Capacity ◽  
Inflation Pressure ◽  
3D Finite Element ◽  
Load Carrying ◽  
Pavement Damage ◽  
New Generation

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.

A Study on the Behavior of Ultrasonic Guided Wave Mode in a Pipe Using a Comb Transducer

2005 ◽  
Vol 297-300 ◽  
pp. 2182-2186
Author(s):  
Ik Keun Park ◽  
Yong Kwon Kim ◽  
Youn Ho Cho ◽  
Won Joon Song ◽  
Yeon Shik Ahn ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Mode Conversion ◽  
Group Velocity Dispersion ◽  
Longitudinal Mode ◽  
Wave Mode ◽  
Guided Wave ◽  
Flexural Mode ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Ultrasonic Guided Wave

A preliminary study of the behavior of ultrasonic guided wave mode in a pipe using a comb transducer for maintenance inspection of power plant facilities has been verified experimentally. Guided wave mode identification is carried out in a pipe using time-frequency analysis methods such as wavelet transform (WT) and short time Fourier transform (STFT), compared with theoretically calculated group velocity dispersion curves for longitudinal and flexural mode. The results are in good agreement with analytical predictions and show the effectiveness of using the time-frequency analysis method to identify the individual guided wave modes. And, It was found out that longitudinal mode (0, 1) is affected by mode conversion less than the other modes. Therefore, L (0, 1) is selected as a optimal mode for evaluating location of the surface defect in a pipe.

A Wall Thinning Detection and Quantification Based on Guided Wave Mode Conversion Features

2006 ◽  
Vol 321-323 ◽  
pp. 795-798 ◽  
Author(s):  
Youn Ho Cho ◽  
Won Deok Oh ◽  
Joon Hyun Lee
Keyword(s):  
Long Range ◽  
Guided Waves ◽  
Velocity Dispersion ◽  
Mode Conversion ◽  
Group Velocity Dispersion ◽  
Wave Mode ◽  
Guided Wave ◽  
Wall Thinning ◽  
Theoretical Analyses ◽  
Data Calibration

This study presents a feasibility of using guided waves for a long-range inspection of pipe through investigation of mode conversion and scattering pattern from edge and wall-thinning in a steel pipe. Phase and group velocity dispersion curves for reference modes of pipes are illustrated for theoretical analyses. Predicted modes could be successfully generated by controlling frequency, receiver angle and wavelength. The dispersive characteristics of the modes from and edge wall-thinning are compared and analyzed respectively. The mode conversion characteristics are distinct depending on dispersive pattern of modes. Experimental feasibility study on the guided waves was carried out to explore wall thinning part in pipe for data calibration of a long range pipe monitoring by comb transducer and laser.

scholarly journals Numerical Investigation on Steel Square HSS Columns Strengthened with Polymer-mortar

2019 ◽  
pp. 1-25
Author(s):  
Khaled M. El-Sayed ◽  
Ahmed S. Debaiky ◽  
Nader N. Khalil ◽  
Ibrahim M. El-Shenawy
Keyword(s):  
Three Dimensional ◽  
Shell Element ◽  
Fe Analysis ◽  
Experimental Results ◽  
Fe Model ◽  
Cross Sectional ◽  
Axial Strength ◽  
Polymer Mortar ◽  
Slender Columns ◽  
Good Agreement

This paper presents the results of finite element (FE) analysis of axially loaded square hollow structural steel (HSS) columns, strengthened with polymer-mortar materials. Three-dimensional nonlinear FE model of HSS slender columns were developed using thin-shell element, considering geometric and material nonlinearity. The polymer-mortar strengthening layer was incorporated using additional layers of the shell element. The FE model has been performed and then verified against experimental results obtained by the authors [1]. Good agreement was observed between FE analysis and experimental results. The model was then used in an extended parametric study to examine selected AISC square HSS columns with different cross-sectional geometries, slenderness ratios, thicknesses of mortar strengthening layer, overall geometric imperfections, and level of residual stresses. The effectiveness of polymer-mortar in increasing the column’s axial strength is observed. The study also demonstrated that polymer-mortar strengthening materials is more effective for higher slenderness ratios. An equivalent steel thickness is also accounted for the mortar strengthened HSS columns to discuss the effectiveness of polymer-mortar strengthening system. The polymer-mortar strengthening system is more effective for HSS columns with higher levels of out-of-straightness. Level of residual stress has a slight effect on the gain in the column’s axial strength strengthened with polymer-mortar.

Analysis of S0/A0 guided wave mode conversion phenomenon

2018 ◽  
Author(s):  
Tomasz Wandowski ◽  
Pawel Malinowski ◽  
Pawel Kudela ◽  
Wieslaw Ostachowicz
Keyword(s):  
Mode Conversion ◽  
Wave Mode ◽  
Guided Wave

scholarly journals Improved Defect Detection Using Adaptive Leaky NLMS Filter in Guided-Wave Testing of Pipelines

2019 ◽  
Vol 9 (2) ◽  
pp. 294 ◽  
Author(s):  
Houman Nakhli Mahal ◽  
Kai Yang ◽  
Asoke Nandi
Keyword(s):  
Signal To Noise Ratio ◽  
Single Point ◽  
Element Model ◽  
Wave Mode ◽  
Guided Wave ◽  
Least Mean Square ◽  
Material Loss ◽  
Optimum Frequency ◽  
Cross Sectional ◽  
Axisymmetric Wave

Ultrasonic guided wave (UGW) testing of pipelines allows long range assessments of pipe integrity from a single point of inspection. This technology uses a number of arrays of transducers, linearly placed apart from each other to generate a single axisymmetric wave mode. The general propagation routine of the device results in a single time domain signal, which is then used by the inspectors to detect the axisymmetric wave for any defect location. Nonetheless, due to inherited characteristics of the UGW and non-ideal testing conditions, non-axisymmetric (flexural) waves will be transmitted and received in the tests. This adds to the complexity of results’ interpretation. In this paper, we implement an adaptive leaky normalized least mean square (NLMS) filter for reducing the effect of non-axisymmetric waves and enhancement of axisymmetric waves. In this approach, no modification in the device hardware is required. This method is validated using the synthesized signal generated by a finite element model (FEM) and real test data gathered from laboratory trials. In laboratory trials, six different sizes of defects with cross-sectional area (CSA) material loss of 8% to 3% (steps of 1%) were tested. To find the optimum frequency, several excitation frequencies in the region of 30–50 kHz (steps of 2 kHz) were used. Furthermore, two sets of parameters were used for the adaptive filter wherein the first set of tests the optimum parameters were set to the FEM test case and, in the second set of tests, the data from the pipe with 4% CSA defect was used. The results demonstrated the capability of this algorithm for enhancing a defect’s signal-to-noise ratio (SNR).

Guided wave propagation in high-speed train axle and damage detection based on wave mode conversion

2015 ◽  
Vol 22 (9) ◽  
pp. 1133-1147 ◽  
Author(s):  
Fucai Li ◽  
Xuewei Sun ◽  
Jianxi Qiu ◽  
Limin Zhou ◽  
Hongguang Li ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Damage Detection ◽  
High Speed ◽  
Mode Conversion ◽  
Wave Mode ◽  
Guided Wave ◽  
High Speed Train ◽  
Guided Wave Propagation
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