Prediction of Ultrasonic Guided Wave Dispersion in Bent Pipes Using Finite Element Analysis and 2-D Fourier Transform

2005 ◽  
pp. 2065-2070
Author(s):  
Sung Jin Song ◽  
Young H. Kim ◽  
Joon Soo Park ◽  
Hyung Ju Yu ◽  
Yong Moo Cheong ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fourier Transform ◽  
Wave Dispersion ◽  
Guided Wave ◽  
Element Analysis ◽  
Ultrasonic Guided Wave

Prediction of Ultrasonic Guided Wave Dispersion in Bent Pipes Using Finite Element Analysis and 2-D Fourier Transform

2005 ◽  
Vol 297-300 ◽  
pp. 2065-2070 ◽  
Author(s):  
Sung Jin Song ◽  
Young H. Kim ◽  
Joon Soo Park ◽  
Hyung Ju Yu ◽  
Yong Moo Cheong ◽  
...  
Keyword(s):  
Finite Element ◽  
Fourier Transform ◽  
Wave Dispersion ◽  
Angular Frequency ◽  
General Purpose ◽  
Guided Wave ◽  
Wave Number ◽  
Element Analysis ◽  
Finite Element Program ◽  
Mode Identification

In this paper, the dispersion curves of a bent cylindrical pipe are obtained by using the 3-dimensional finite element modeling and 2-dimenstional Fourier transform. The transient responses of the bent pipe are calculated by using a general-purpose finite element program, and the displacements are extracted at a series of sequential points as a function of spatial position and time, u(x,t). Then 2-dimentional FFT of u (x,t) offers U (k,ω), the relation between wave number and angular frequency so that the phase velocity and group velocity can be calculated. In addition, verification of the result is made by the mode identification using wavelet transform. The modes invoked by both methods agree very well.

Finite Element Analysis of Blower Impeller Using Cyclic Symmetry

2007 ◽  
Vol 353-358 ◽  
pp. 1082-1085
Author(s):  
Chang Boo Kim ◽  
Young Chul Ahn ◽  
Bo Yeon Kim ◽  
Chong Du Cho ◽  
Hyeon Gyu Beom
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fourier Transform ◽  
Natural Vibration ◽  
Cyclic Symmetry ◽  
Static Characteristics ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Non Linear ◽  
Comparison Of The Results

In this paper, we present an efficient method for conducting a finite element analysis of a structure with cyclic symmetry and apply the method to analyze the natural vibration and linear and non-linear static characteristics of a blower impeller. A blower impeller is composed of circumferentially repeated substructures. The whole structure is partitioned into substructures, and the finite element analysis can thus be performed with one representative substructure by using the transformed equations for each number of nodal diameters, which are derived from a discrete Fourier transform. We calculated the natural vibration and linear and non-linear static characteristics of a blower impeller without a stiffening ring, and with small as well as large stiffening rings, respectively. The accuracy and efficiency of the presented method are verified by comparison of the results obtained from the analysis using a substructure to those obtained using the whole structure.

Revisiting the bearing stresses in webs of crane runway girders under wheel loads

2018 ◽  
Vol 21 (12) ◽  
pp. 1792-1801
Author(s):  
Tong Genshu ◽  
Xuan Zejun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fourier Transform ◽  
Shear Deformation ◽  
Infinite Plane ◽  
Element Analysis ◽  
Closed Form Solutions ◽  
Bearing Stress ◽  
The Fourier Transform ◽  
The Moment

This article revisited the problem of local bearing stress in webs of I-section girders supporting overhead cranes. Finite element analysis was carried out to determine the equivalent bearing length. It was found that the moment of inertia of the rail and the web thickness of the girder are the two predominant factors. The equivalent bearing lengths by the finite element analysis were found to be significantly smaller than that predicted by the formula in various codes. Analysis revealed that the differences come from the shear deformation in the rail and the load position on the rail. Closed-form solutions for a Timoshenko’s beam on a semi-infinite plane subjected to a concentrated or distributed load were presented in which the Fourier transform is used. After the shear deformation was considered and a widened load distribution length on the centroid axis of the rail, which considered the load dispersion in an angle of 35°–40° from the top of the rail to the centroid axis, are adopted in the Fourier transform solution, the analytical results are in good agreement with finite element analysis. Formulas of equivalent bearing lengths for two types of rails used in China are recommended for practical use.

Finite Element Analysis of Corrosion Damaged Pipeline Using PZT-Based Ultrasonic Guided Wave Energy Method

2014 ◽  
Vol 1079-1080 ◽  
pp. 368-373
Author(s):  
Shi Yan ◽  
Xin Zi Yuan ◽  
Nai Zhi Zhao ◽  
Wei Wang ◽  
Yang Cheng
Keyword(s):  
Finite Element ◽  
Wave Energy ◽  
Energy Method ◽  
Corrosion Damage ◽  
Guided Wave ◽  
Element Analysis ◽  
Finite Element Software ◽  
Ultrasonic Guided Wave ◽  
Radial Depth ◽  
Pipeline Structures

PZT-based ultrasonic guided wave has played an important role in health monitoring of pipeline structures. By using the PZT-based ultrasonic guided wave energy method and finite element software ABAQUS, the numerical simulation is performed to analyze various corrosion damaged pipeline structures, emphasizing on the damage identification, sensitivity analysis and longitudinal energy attenuation of the guided wave along various corrosion damaged pipelines. The preliminary analysis of the echo signals shows that the grass-like clutter wave belongs to echoes of the corrosion damage of the pipeline, and the wave energy spreads faster here. At the same time, by frequency spectrum analysis of the echo signal, the relationship between the reflection coefficient and the radial depth of defection is made which can be used to approximately evaluate geometrical dimension of the damage.

Sign in / Sign up

Export Citation Format

Share Document