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A boundary element method for Simulation of Deformable Objects

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Journal of Computer Science & Technology 1996年第5期11卷 497-506页

作者：徐美和唐泽圣 CADCenter DepartmentofComputerScienceTsinghuaUniversityBeijing100084 CADCenter DepartmentofComputer

In this paper, a boundary element method is first applied to real-time animation of deformable objects and to simplify data preparation. Next, the visible external surface of the object in deforming process is represented by B-spline surface, whose control points are embedded in dynamic equations of BEM. Finally, the above method is applied to anatomical simulation. A pituitary model in human brain, which is reconstructed from a set of anatomical sections, is selected to be the deformable object under action of virtual tool such as scalpel or probe. It produces fair graphic realism and high speed performance. The results show that BEM not only has less computational expense than FEM, but also is convenient to combine with the 3D reconstruction and surface modeling as it enables the reduction of the dimensionality of the problem by one.

关键词： Physically based modeling animation simulation boundary element method B-spline surface representation

boundary element method FOR CALCULATING ACOUSTIC RADIATION FROM CLOSED SURFACE WITH PRESCRIBED VELOCITY DISTRIBUTION

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Chinese Journal of Acoustics 1989年第2期8卷 111-120页

作者： Zhao, Jian Wang, Hongzhen Zhu, Wuhua Zhong Shan Univ

The application of BEM to calculate acoustic radiation from closed surface in an infinite acoustic medium has the advantages of less memory space, higher accuracy and faster calculating speed. However, the singular integrals and the nonuniqueness problem of surface helmholtz equation at characteristic frequencies should be dealt with. It is suggested in this paper that combination of the interior Helmholtz equation and its derivatives with respect to the coordinate components of an interior point forms an extra equation, in order to solve the problems of acoustic radiation at various frequencies with surface Helmholtz equation; on the area which includes singular point, the singular integrals are converted to ordinary ones by polar coordinate transformation. As an example, the acoustic radiation field of closed axisymmetric surfaces with prescribed surface velocity distribution is calculated in this paper.

关键词： Computers Applications Mathematical Models Mathematical Techniques boundary element method

boundary element method FOR MODEL ANALYSIS OF 2-D COMPOSITE STRUCTURE

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Acta Mechanica Solida Sinica 1998年第1期11卷 63-71页

作者： Zou Jing Li Zailiang Zhong Weifang Huazhong Univ Sci & Technol Dept Mech Wuhan 430074 Peoples R China

The boundary element method is used for he modal analysis of freevibration of 2-D composite structures in this paper. Since theparticular solution method is used to treat the terms of body forces(inertial forces) in the equation of motion, only static fundamentalsolutions are needed in solving the problem. For an isotropiccantilever beam, the numerical results obtained by using the BEMpresented in this paper are in good agreement, with those of usingFEM or other BEM, but this BEM can also be used to analyze problemsfor anisotropic materials.

关键词： composite structure boundary element method particular solution method

boundary element method FOR ARBITRARY ELASTIC THIN SHELL

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Acta Mechanica Sinica 1992年第4期8卷 355-362页

作者：郑国英嵇醒 Southeast University Nanjing 210018China Tongji UniversityShanghai 200092China

In this paper,a boundary element scheme for arbitrary elastic thin shells is elaborated,Based on BEM of 3D linear elasticity and Kirchhoff's hypothesis,boundary integral equations for shells are deduced. As a result,only Kelvin's solution is used,the difficulty,in finding a fundamental solution of arbitrary shells is successfully avoided.

关键词： arbitrary shells boundary element method Kelvin's solution

boundary element method for High－Voltage Terminations and 2－DBEM Simulation Of MZ－JTE

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The Journal of China Universities of Posts and Telecommunications 1994年第2期1卷 36-46页

作者： Liang Sujun(Cornputer and CAD research division . Xi’an instltute of Postsand Telecomrnunications . Xi’an 710061 , P. R. China) A NDLuo Jinsheng(Departrnent of Electronic Engineering . Xi’an Jiaototig Universitles ,Xi’an 710049 . P. R. Ctiina)

one of the mosl *** areus in highvollage devices and IC designs is the edge.(junction ) termination. A novel numerical lechnique ,boundary Elenient method ( BEM) for analysis of Critical Eleclric Field (CEFBEM) in terminations is presented form a new poitl of view. Based onit.a 2-D Untfied BEM program for simulating the Multiple-Zone Junction Termination Extension (MZ-JTE ) ,UBPMJTE . is drveloped and the polential and field distributions in MZ-JTE a,are calculated. The peak elecl,ic field and the effecl o., the surface slales are investigaled. The. BEM resulis *** agreement with ones obtained by the finite diffcrence, ,method (FDM) and the finite element method( FEM) . This work has opened a new way jor the sirnulalions of complex terminations ,is and design opli-

关键词： high-voltage lermination numerical analysis boundary element method

Three-dimensional acoustic propagation model for shallow waters based on an indirect boundary element method

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Chinese Physics B 2023年第5期32卷 485-495页

作者： Edmundo F.Lavia Juan D.Gonzalez Silvia Blanc Acoustic Propagation Department Argentinian Navy Research Office(DIIV)Buenos Aires 1638Argentina UNIDEF(National Council of Scientific and Technical Research/Ministry of Defense) Buenos AiresArgentina

This work has a two-fold *** the one hand,the theoretical formulation of a three-dimensional(3D)acoustic propagation model for shallow waters with a constant sound speed is presented,based on the boundary element method(BEM),which uses a half-space Green function instead of the more conventional free-space Green *** the other hand,a numerical implementation is illustrated to explore the formulation in simple idealized cases,controlled by a few parameters,which provides necessary tests for the accuracy and performance of the *** half-space Green's function,which has been previously used in scattering and diffraction,adds terms to the usual expressions of the integral operators without altering their continuity *** against the wavenumber integration solution of the Pekeris waveguide suggest that the model allows an adequate prediction for the acoustic ***,numerical experiments in relation to the necessary mesh size for the description of the water-marine sediment interface lead to the conclusion that a transmission loss prediction with acceptable accuracy can be obtained with the use of a limited mesh around the desired evaluation region.

关键词： three-dimensional acoustic propagation boundary element method half-space Green function

Introducing an effective coherence function to generate non-uniform ground motion on topographic site using time-domain boundary element method

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Earthquake Engineering and Engineering Vibration 2021年第1期20卷 89-100页

作者： Mohsen Isari Reza Tarinejad Faculty of Civil Engineering University of TabrizTabrizEast Azerbaijan ProvinceIran

In this study,a comprehensive parametric analysis was performed on non-uniform excitation of V-shaped topography using the boundary element method in time *** this purpose,wave scattering analysis was carried out on a topography subjected to the SV-wave for different predominant frequencies and shape *** on the numerical results,new coherence and time delay functions are proposed to generate non-uniform ground motion for topographic *** efficiency and accuracy of the proposed functions for real engineering problems are indicated by comparison with observations reported in previous literature.

关键词： site effect time delay boundary element method amplification coherence function

Modeling tail bubble dynamics during the launch of an underwater vehicle using the boundary element method

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Journal of Hydrodynamics 2022年第3期34卷 434-443页

作者： Shao-hua Cheng Xiao-bo Quan Sai Zhang Tian-yuan Zhang Shuai Li College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Beijing Institute of Astronautical Systems Engineering Beijing100076China China Academy of Launch Vehicle Technology Beijing100076China

A tail bubble is generated behind a high-speed vehicle at the early stage of the underwater launch *** tail bubble dynamic behavior involves expansion,overexpansion,contraction,pinch-off and jet formation,and it significantly influences the vehicle’s ***,the tail bubble dynamic behavior is an issue not very well *** paper establishes a numerical model for the interaction between the tail bubble and the vehicle based on the boundary element method(BEM)to gain new insight into this *** BEM results are compared to a computational fluid dynamics model to validate the numerical model,and good agreement is ***,a convergence test of the BEM model is conducted to verify its independence of the mesh *** influence of some governing parameters on the evolution of the tail bubble is then systematically studied,focusing on its maximum radius,pinch-off time,and pinch-off *** are two pinch-off position regimes of the tail bubble,one at the bottom and the other near the middle.

关键词： Underwater launch tail bubble bubble dynamics boundary element method

Simulating regular wave propagation over a submerged bar by boundary element method model and Boussinesq equation model

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Chinese Physics B 2013年第2期22卷 308-313页

作者：李爽何海伦 Department of Ocean Science and Engineering Zhejiang University Key Laboratory of Ocean Circulation and Waves Chinese Academy of Sciences State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographySOA

Numerical models based on the boundary element method and Boussinesq equation are used to simulate the wave transform over a submerged bar for regular *** the boundary-element-method model the linear element is used,and the integrals are computed by analytical *** Boussinesq-equation model is the well-known FUNWAVE from the University of *** compare the numerical free surface displacements with the laboratory data on both gentle slope and steep slope,and find that both the models simulate the wave transform *** further compute the agreement indexes between the numerical result and laboratory data,and the results support that the boundary-element-method model has a stable good performance,which is due to the fact that its governing equation has no restriction on nonlinearity and dispersion as compared with Boussinesq equation.

关键词： numerical wave tank boundary element method Boussinesq equation