Reconstruction of Scatterer Shape from Relative Intensity of Scattered Field by Using Linearized Boundary Element Method

2020 ◽  
Vol E103.C (2) ◽  
pp. 30-38 ◽  
Author(s):  
Jun-ichiro SUGISAKA ◽  
Takashi YASUI ◽  
Koichi HIRAYAMA
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Relative Intensity ◽  
Scattered Field ◽  
Element Method

scholarly journals Investigation of Rayleigh wave interaction with surface defects

2019 ◽  
Vol 13 (3) ◽  
pp. 95-103
Author(s):  
Phan Hai Dang ◽  
Le Duc Tho ◽  
Le Quang Hung ◽  
Dao Duy Kien
Keyword(s):  
Boundary Element Method ◽  
Rayleigh Wave ◽  
Boundary Element ◽  
Half Space ◽  
Scattered Field ◽  
Surface Defects ◽  
Reciprocity Theorem ◽  
Approximate Theory ◽  
Linear Superposition ◽  
Element Method

The current article is concerned with the interaction of Rayleigh waves with surface defects of arbitrary shape in a homogeneous, isotropic, linearly elastic half-space. Using a linear superposition principle, the interaction generates a scattered field which is equivalent to the field radiated from a distribution of horizontal and vertical tractions on the surface of the defect. These tractions are equal in magnitude but opposite in sign to the corresponding tractions obtained from the incident wave. The scattered field is then computed as the superposition of the displacements radiated from the tractions at every point of the defect surface using the reciprocity theorem approach. The far-field vertical displacements are compared with calculations obtained by the boundary element method (BEM) for circular, rectangular, triangular and arbitrary-shaped defects. Comparisons between the theoretical and BEM results, which are graphically displayed, are in excellent agreement. It is also discussed the limitations of the proposed approximate theory. Keywords: half-space; Rayleigh wave; surface defect; reciprocity theorem; boundary element method (BEM).

scholarly journals Boundary-Element Analysis of Magnetic Polarization Tensor for Metallic Cylinder

2021 ◽  
Author(s):  
Zhongwei Jin ◽  
ganghua qin ◽  
haidong fan ◽  
ruochen huang ◽  
ziqi chen ◽  
...  
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Scattered Field ◽  
Excitation Frequency ◽  
Computation Method ◽  
Polarization Tensor ◽  
Magnetic Polarization ◽  
Element Analysis ◽  
Metallic Sample ◽  
Element Method

The magnetic polarization tensor has a promising capability of determining the geometry and material properties of metallic samples. In this paper, a novel computation method is proposed to estimate the magnetic polarization tensors for the metallic samples using the boundary element method. In this method, the metallic sample is placed in a uniformly distributed magnetic field. Based on assumptions that the excitation frequency and/or the conductivity of the sample is very high, the metallic sample is regarded as a perfect electrical conductor (PEC). Therefore, the scattered field at a certain distance can be simulated. By utilising the boundary element method, the magnetic polarization tensor can be derived from the simulated scattered field. The theoretical calculation is presented and simulations and experiments have been carried out to validate the proposed method. The results from the simulation are matched with the analytical solution for the case of sphere samples. Moreover, there is a good agreement between the simulation results and the experimental results for the copper cylindrical samples.

A BOUNDARY-ELEMENT METHOD FOR ATOMIZATION OF A FINITE LIQUID JET

1995 ◽  
Vol 5 (6) ◽  
pp. 621-638 ◽  
Author(s):  
J. H. Hilbing ◽  
Stephen D. Heister ◽  
C. A. Spangler
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Liquid Jet ◽  
Element Method

Application of the Boundary Element Method and Modal Analysis to Tire Acoustics Problems

1993 ◽  
Vol 21 (2) ◽  
pp. 66-90 ◽  
Author(s):  
Y. Nakajima ◽  
Y. Inoue ◽  
H. Ogawa
Keyword(s):  
Finite Element ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Traffic Noise ◽  
Noise Prediction ◽  
Prediction System ◽  
Tire Noise ◽  
Acoustic Contribution ◽  
Element Method

Abstract Road traffic noise needs to be reduced, because traffic volume is increasing every year. The noise generated from a tire is becoming one of the dominant sources in the total traffic noise because the engine noise is constantly being reduced by the vehicle manufacturers. Although the acoustic intensity measurement technology has been enhanced by the recent developments in digital measurement techniques, repetitive measurements are necessary to find effective ways for noise control. Hence, a simulation method to predict generated noise is required to replace the time-consuming experiments. The boundary element method (BEM) is applied to predict the acoustic radiation caused by the vibration of a tire sidewall and a tire noise prediction system is developed. The BEM requires the geometry and the modal characteristics of a tire which are provided by an experiment or the finite element method (FEM). Since the finite element procedure is applied to the prediction of modal characteristics in a tire noise prediction system, the acoustic pressure can be predicted without any measurements. Furthermore, the acoustic contribution analysis obtained from the post-processing of the predicted results is very helpful to know where and how the design change affects the acoustic radiation. The predictability of this system is verified by measurements and the acoustic contribution analysis is applied to tire noise control.

Explicit Kutta condition for unsteady two-dimensional high-order potential boundary element method

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1080-1081
Author(s):  
Giuseppe Davi ◽  
Rosario M. A. Maretta ◽  
Alberto Milazzo
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
High Order ◽  
Two Dimensional ◽  
Kutta Condition ◽  
Element Method
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