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Visualization of Flow Field Around a Vibrating Pipeline Within an Equilibrium Scour Hole
Published on: August 26, 2019
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Low frequency axisymmetric longitudinal guided waves in eccentric annular cylinders
Roson Kumar Pattanayak1, Prabhakaran Manogharan1, Krishnan Balasubramaniam1
1Centre for Nondestructive Evaluation, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India.
The Journal of the Acoustical Society of America
|June 22, 2015
Summary
Axially uniform eccentricity in pipes disrupts the L(0,2) guided wave mode, causing it to confine to thinner sections and reduce velocity. This study explores feature-guiding effects in circular tubes.
Area of Science:
- Solid Mechanics
- Acoustics
- Wave Propagation
Background:
- Guided wave propagation in circular pipes is crucial for structural health monitoring.
- Axial eccentricity can significantly alter wave behavior in waveguides.
- Understanding mode confinement and velocity changes is vital for accurate analysis.
Purpose of the Study:
- To investigate the impact of axially uniform eccentricity on the L(0,2) guided wave mode in circular pipes.
- To analyze the resulting changes in modal structures and velocities.
- To elucidate the underlying physics of feature-guiding and mode confinement.
Main Methods:
- Semi-analytical finite element method (FEM) for primary analysis.
- Fully three-dimensional FEM models for detailed simulation.
- Experimental validation to confirm numerical findings.
Main Results:
- Even minor eccentricity breaks the axisymmetry of the L(0,2) mode.
- The wave mode becomes confined to the thinned region of the eccentric pipe.
- A reduction in the L(0,2) mode's velocity is observed due to eccentricity.
Conclusions:
- Axial eccentricity fundamentally alters L(0,2) mode behavior in pipes.
- The findings align with known feature-guiding and mode confinement phenomena.
- Eccentricity must be considered for accurate guided wave analysis in real-world pipe structures.
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