scholarly journals Analysis of Preload Effect in the Axisymmetric Damped Steel Wire Using Ultrasonic Guided Wave Monitoring

2020 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Jothi Saravanan Thiyagarajan

Guided ultrasonic wave propagation characteristics in the axisymmetric prestressed viscoelastic waveguide, using the semi-analytical finite element (SAFE) method, are studied broadly for acoustic emission monitoring. For the numerical investigation, a single high strength steel wire is considered. The SAFE method for an axisymmetric cross-section in cylindrical-coordinates is utilized to analyze the two main influencing factors of steel wire in a practical scenario, namely, material damping and initial tension. For pre-stress effect, the calculation shows that the initial tensile stress can increase and decrease the energy velocity and attenuation factor of most modal waves above the cut-off frequency, which is linear.

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5029
Author(s):  
Jothi Saravanan Thiyagarajan

In this paper, the guided ultrasonic wave propagation characteristics in the axisymmetric pre-stressed viscoelastic waveguide for acoustic emission (AE) monitoring, using the semi-analytical finite element (SAFE) method, is studied broadly. For the numerical investigation, a single high-strength steel wire is considered. A comprehensive and in-depth study on the AE signal’s propagation characteristics is carried out based on the SAFE method. Both undamped and damped waveguides are considered for attaining SAFE solutions and presented in a detailed manner. The SAFE method for an axisymmetric cross-section in cylindrical coordinates analyzes the two main influencing factors of steel wire in a practical scenario: Material damping and initial tension. For the effect of initial stress, the calculation shows that the initial tensile stress can increase and decrease the energy velocity and attenuation factor of most modal waves above the cut-off frequency, and the effect is linear. Some longitudinal wave modes in the high-frequency region show their potential for AE monitoring as these modes have a low attenuation factor and small external surface vibration. By considering various states of initial stress in a damped waveguide, the effect of pre-stress on the dispersion characteristics is understood in a better manner. A non-destructive testing (NDT) mechanism for pre-stressed steel wire using AE monitoring is proposed for the health monitoring of structures.


2006 ◽  
Vol 321-323 ◽  
pp. 799-803 ◽  
Author(s):  
Ik Keun Park ◽  
Yong Kwon Kim ◽  
Hyun Mook Kim ◽  
Won Joon Song ◽  
Yong Sang Cho

Conventional non-destructive techniques for inspection of weld in pipelines require significant test time and high cost. In this paper, a study in the application of ultrasonic guided waves to long range inspection of the pipeline is presented. The characteristics and setup of a long range guided wave inspection system and experimental results in pipes of various diameters are introduced. The experimental results in mock-up pipes with cluster type defects show that the limit of detectable wall thickness reduction with this guided wave system is 2~3% in the pipe cross section area and the wall thickness reduction of 5% in cross section area can be detected when actual detection level is used. Therefore, the applicability of the ultrasonic guided wave technique to long range pipeline inspection for wall thickness reduction is verified.


2020 ◽  
Vol 309 ◽  
pp. 03035
Author(s):  
Longxiang Zhu ◽  
Guangming Kong ◽  
Haibing Zhang ◽  
Xiangyang Yu

The guided waves in the elbow was analyzed using semi- analytical finite element method, which was used to calculate the dispersion curves, along with the vibration deformation and energy flow density distribution of the elbow cross-section. The L(0,1) mode guided wave was used to detect different defects in the U-shaped pipeline in experiment. The average experimental velocity of L(0,1) mode in U-shaped pipeline was between the theoretical velocities of the straight pipe and the elbow, due to the different velocities in the two parts. The detection sensitivity difference of L(0,1) mode guided wave to defects in intrados and extrados of the elbow was analyzed, the experimental result showed that the reflected signal amplitude of defect in extrados was significantly larger than the defect in intrados, which was consistent with the energy flow density distribution in elbow cross-section.


2019 ◽  
Vol 19 (2) ◽  
pp. 481-494 ◽  
Author(s):  
Javad Rostami ◽  
Peter W Tse ◽  
Maodan Yuan

Elevator wire ropes with polymer cores hold and hoist heavy fluctuating loads in a corrosive environment. Such working condition causes metal fatigue, which together with abrasion around pulleys leads to progressive loss of the metallic cross section. This can be seen in the forms of a roughened and pitted surface of the ropes, reduction in diameter, and broken wires. Therefore, their deterioration must be monitored so that any unexpected damage or corrosion can be detected before it causes a fatal accident. Ultrasonic-guided wave-based inspection, which has proved its capability in nondestructive testing of platelike structures such as tubes and pipes, can monitor the cross section of wire ropes in their entire length from a single point. However, guided waves have drawn less attention for defect detection purposes in wire ropes. This article reports the condition monitoring of a steel wire rope from a hoisting elevator with broken wires as a result of corrosive environment and fatigue. Finite element analysis was conducted as a baseline to study guided wave propagation in wire ropes and plot dispersion curves. Guided wave propagation in wire ropes was experimentally investigated on a newly built cable stretching machine equipped with a load sensor under different amount of tensile loading. To expose the indication of broken wires, the recorded signals were analyzed by tailor-made continuous wavelet transform called tone burst wavelet.


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