Direct Nondestructive Algorithm for Shape Defects Evaluation

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Sebastián Ossandón ◽  
José Klenner ◽  
Camilo Reyes
Keyword(s):  
Boundary Element Method ◽  
Nondestructive Evaluation ◽  
Numerical Method ◽  
Boundary Element ◽  
Stability And Convergence ◽  
Nondestructive Analysis ◽  
Numerical Examples ◽  
Galerkin Boundary Element Method ◽  
Shape Differentiation ◽  
Analysis Stability

An efficient numerical method based on a rigorous integral formulation is used to calculate precisely the acoustic eigenvalues of complex shaped objects and their associated eigenvectors. These eigenvalues are obtained and later used in acoustic nondestructive evaluation. This study uses the eigenvalues to implement a simple acoustic shape differentiation algorithm that is the key in our direct nondestructive analysis. Stability and convergence of the Galerkin boundary element method used herein are discussed. Finally, some numerical examples are shown.

Boundary Element Method Used in Random Response Calculation of the Plate-Beam Structure

1991 ◽  
Author(s):  
J. M. Zhu ◽  
L. Huang
Keyword(s):  
Boundary Element Method ◽  
Numerical Method ◽  
Boundary Element ◽  
Pressure Fluctuation ◽  
Random Vibration ◽  
Power Plants ◽  
Measured Data ◽  
Random Response ◽  
Beam Structure ◽  
Element Method

Abstract The furnace walls of the large boilers in power plants are combined structures consisting of orthotopic plate and equally spaced beams, which are usually submitted to random vibration under the excitation of the pressure fluctuation induced by combustion in the furnace. In this paper, a numerical method based on BEM to compute the random response of the structure is offered. The agreement between the computing results and the measured data in a practical example verifies the effectiveness of the method.

scholarly journals Application of hybrid boundary element method: Example of semishperical ground inhomogeneity

2014 ◽  
Vol 11 (4) ◽  
pp. 617-628
Author(s):  
Nenad Cvetkovic ◽  
Sasa Ilic ◽  
Dragan Vuckovic ◽  
Dejan Jovanovic ◽  
Dejan Krstic
Keyword(s):  
Boundary Element Method ◽  
Point Source ◽  
Numerical Method ◽  
Boundary Element ◽  
Program Package ◽  
Image Theory ◽  
Field Analysis ◽  
Grounding System ◽  
Em Field ◽  
Element Method

One new, so-called hybrid boundary element method (HBEM) is presented in this paper. It is a recently proposed numerical method for stationary and quasi-stationary EM field analysis. The method application is illustrated on the example of solving the problem of modelling hemispherical ground inhomogeneity influence on grounding system. The applied procedure also includes using of quasi-stationary image-theory. The obtained results are compared with those ones based on using the Green?s function for the point source inside semi-spherical inhomogeneities as well as with the results obtained by applying COMSOL program package.

Removing Non-Uniqueness in Symmetric Galerkin Boundary Element Method for Elastostatic Neumann Problems and its Application to Half-Space Problems

2020 ◽  
Vol 36 (6) ◽  
pp. 749-761
Author(s):  
Y. -Y. Ko
Keyword(s):  
Boundary Element Method ◽  
Rigid Body ◽  
Boundary Element ◽  
Integral Equations ◽  
Half Space ◽  
Boundary Integral Equations ◽  
Boundary Integral ◽  
Neumann Problems ◽  
Galerkin Boundary Element Method ◽  
Element Method

ABSTRACTWhen the Symmetric Galerkin boundary element method (SGBEM) based on full-space elastostatic fundamental solutions is used to solve Neumann problems, the displacement solution cannot be uniquely determined because of the inevitable rigid-body-motion terms involved. Several methods that have been used to remove the non-uniqueness, including additional point support, eigen decomposition, regularization of a singular system and modified boundary integral equations, were introduced to amend SGBEM, and were verified to eliminate the rigid body motions in the solutions of full-space exterior Neumann problems. Because half-space problems are common in geotechnical engineering practice and they are usually Neumann problems, typical half-space problems were also analyzed using the amended SGBEM with a truncated free surface mesh. However, various levels of errors showed for all the methods of removing non-uniqueness investigated. Among them, the modified boundary integral equations based on the Fredholm’s theory is relatively preferable for its accurate results inside and near the loaded area, especially where the deformation varies significantly.

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