scholarly journals Modeling Three-dimensional Ultrasonic Guided Wave Propagation and Scattering in Circular Cylindrical Structures using Finite Element Approach

2011 ◽  
Vol 22 ◽  
pp. 112-118 ◽  
Author(s):  
Ming-fang Zheng ◽  
Chao Lu ◽  
Guo-zhu Chen ◽  
Ping Men
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Three Dimensional ◽  
Guided Wave ◽  
Cylindrical Structures ◽  
Finite Element Approach ◽  
Ultrasonic Guided Wave ◽  
Guided Wave Propagation ◽  
Element Approach

Guided wave excitation and propagation in damped composite plates

2018 ◽  
Vol 18 (3) ◽  
pp. 690-714 ◽  
Author(s):  
Hanfei Mei ◽  
Victor Giurgiutiu
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Composite Plates ◽  
Guided Wave ◽  
Material Behavior ◽  
Complex Frequency ◽  
Material Damping ◽  
Wave Excitation ◽  
Finite Element Approach ◽  
Element Approach

Guided wave attenuation in composites due to material damping is strong, anisotropic, and cannot be neglected. Material damping is a critical parameter in selection of a particular wave mode for long-range structural health monitoring in composites. In this article, a semi-analytical finite element approach is presented to model guided wave excitation and propagation in damped composite plates. The theoretical framework is formulated using finite element method to describe the material behavior in the thickness direction while assuming analytical expressions in the wave propagation direction along the plate. In the proposed method, the Kelvin–Voigt damping model using a complex frequency-dependent stiffness matrix is utilized to account for anisotropic damping effects of composites. Thus, the existing semi-analytical finite element approach is being extended to include material damping effect. Theoretical predictions are experimentally validated using scanning laser Doppler vibrometer measurements of guided wave propagation generated by a circular piezoelectric wafer active sensor transducer in a unidirectional carbon fiber reinforced polymer composite plate. The proposed method achieves good agreement with the experimental results.

Ultrasonic Guided Wave Testing of Finned Tubing

2015 ◽  
Author(s):  
Owen M. Malinowski ◽  
Matthew S. Lindsey ◽  
Jason K. Van Velsor
Keyword(s):  
Wave Propagation ◽  
Guided Waves ◽  
Tube Wall ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Complex Nature ◽  
Inspection Method ◽  
Ultrasonic Guided Wave ◽  
Guided Wave Propagation ◽  
Wave Modes

In the past few decades, ultrasonic guided waves have been utilized more frequently Non-Destructive Testing (NDT); most notably, in the qualitative screening of buried piping. However, only a fraction of their potential applications in NDT have been fully realized. This is due, in part, to their complex nature, as well as the high level of expertise required to understand and utilize their propagation characteristics. The mode/frequency combinations that can be generated in a particular structure depend on geometry and material properties and are represented by the so-called dispersion curves. Although extensive research has been done in ultrasonic guided wave propagation in various geometries and materials, the treatment of ultrasonic guided wave propagation in periodic structures has received little attention. In this paper, academic aspects of ultrasonic guided wave propagation in structures with periodicity in the wave vector direction are investigated, with the practical purpose of developing an ultrasonic guided wave based inspection technique for finned tubing. Theoretical, numerical, and experimental methods are employed. The results of this investigation show excellent agreement between theory, numerical modeling, and experimentation; all of which indicate that ultrasonic guided waves will propagate coherently in finned tube only if the proper wave modes and frequencies are selected. It is shown that the frequencies at which propagating wave modes exist can be predicted theoretically and numerically, and depend strongly on the fin geometry. Furthermore, the results show that these propagating wave modes are capable of screening for and identifying the axial location of damage in the tube wall, as well as separation of the fins from the tube wall. The conclusion drawn from these results is that Guided Wave Testing (GWT) is a viable inspection method for screening finned tubing.

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