Boundary element formulation applied to multi-fractured bodies

An approach to developing a general technique for constructing reduced-order models of unsteady flows about three-dimensional complex geometries is presented. The boundary element method along with the potential flow is used to analyze unsteady flows over two-dimensional airfoils, three-dimensional wings, and wing-body configurations. Eigenanalysis of unsteady flows over a NACA 0012 airfoil, a three-dimensional wing with the NACA 0012 section and a wing-body configuration is performed in time domain based on the unsteady boundary element formulation. Reduced-order models are constructed with and without the static correction. The numerical results demonstrate the accuracy and efficiency of the present method in reduced-order modeling of unsteady flows over complex configurations.

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A boundary element formulation for a class of non-local damage models

International Journal of Solids and Structures ◽

10.1016/s0020-7683(98)00159-0 ◽

1999 ◽

Vol 36 (24) ◽

pp. 3617-3638 ◽

Cited By ~ 14

Author(s):

R. García ◽

J. Flórez-López ◽

M. Cerrolaza

Keyword(s):

Boundary Element ◽

Element Formulation ◽

Local Damage ◽

Damage Models ◽

Non Local

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Theory of a Time Domain Boundary Element Development for the Dynamic Analysis of Coupled Multiphase Porous Media

Journal of Multiscale Modelling ◽

10.1142/s175697371750007x ◽

2017 ◽

Vol 08 (03n04) ◽

pp. 1750007

Author(s):

Pooneh Maghoul ◽

Behrouz Gatmiri

Keyword(s):

Boundary Element ◽

Time Domain ◽

Unsaturated Soils ◽

Water Pressure ◽

Domain Boundary ◽

Fundamental Solutions ◽

Element Formulation ◽

Inertia Effects ◽

Coupled Equations ◽

The Time Domain

This paper presents an advanced formulation of the time-domain two-dimensional (2D) boundary element method (BEM) for an elastic, homogeneous unsaturated soil subjected to dynamic loadings. Unlike the usual time-domain BEM, the present formulation applies a convolution quadrature which requires only the Laplace-domain instead of the time-domain fundamental solutions. The coupled equations governing the dynamic behavior of unsaturated soils ignoring contributions of the inertia effects of the fluids (water and air) are derived based on the poromechanics theory within the framework of a suction-based mathematical model. In this formulation, the solid skeleton displacements [Formula: see text], water pressure [Formula: see text] and air pressure [Formula: see text] are presumed to be independent variables. The fundamental solutions in Laplace transformed-domain for such a dynamic [Formula: see text] theory have been obtained previously by authors. Then, the BE formulation in time is derived after regularization by partial integrations and time and spatial discretizations. Thereafter, the BE formulation is implemented in a 2D boundary element code (PORO-BEM) for the numerical solution. To verify the accuracy of this implementation, the displacement response obtained by the boundary element formulation is verified by comparison with the elastodynamics problem.

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A boundary element formulation for radiation of acoustic waves from axisymmetric bodies with arbitrary boundary conditions

The Journal of the Acoustical Society of America ◽

10.1121/1.405482 ◽

1993 ◽

Vol 93 (2) ◽

pp. 631-639 ◽

Cited By ~ 24

Author(s):

Benjamin Soenarko

Keyword(s):

Boundary Conditions ◽

Boundary Element ◽

Acoustic Waves ◽

Element Formulation ◽

Arbitrary Boundary ◽

Arbitrary Boundary Conditions ◽

Axisymmetric Bodies

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A Boundary Element Method for Multi-Body Contact Problems and its Application to the Analysis of a Huge Excavator

ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium ◽

10.1115/cie1995-0760 ◽

1995 ◽

Author(s):

Chong-De Liu ◽

Jiyuan Yu ◽

Xiaoming Wang

Keyword(s):

Boundary Element Method ◽

Boundary Element ◽

Contact Problems ◽

Fortran Program ◽

Boundary Integral ◽

Element Formulation ◽

Body Contact ◽

Boundary Integral Formulation ◽

Discretization Technique ◽

Multi Body

Abstract The derivation of a boundary integral formulation and discretization technique in terms of boundary elements for the solution of multi-body contact problems has been carried out. A FORTRAN program has been developed based on this boundary element formulation and has been applied to the stress analysis of a huge caterpillar excavator woth 16 m3 bucket capacity.

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Study on Temperature Distribution of Pebble-Bed HTR Fuel Element by Using Boundary Element Method

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2013-97454 ◽

2013 ◽

Author(s):

Haitao Wang ◽

Xin Wang

Keyword(s):

Fuel Element ◽

Boundary Element ◽

Large Scale ◽

Maximum Temperature ◽

Element Formulation ◽

Desktop Computer ◽

Pebble Bed ◽

Graphite Matrix ◽

Fuel Particles ◽

Fuel Elements

Spherical fuel elements with a diameter of 60mm are basic units of the nuclear fuel for the pebble-bed high temperature gas-cooled reactor (HTR). Each fuel element is treated as a graphite matrix containing around 10,000 randomly distributed fuel particles. The essential safety concept of the pebble-bed HTR is based on the objective that maximum temperature of the fuel particles does not exceed the design value. In this paper, a microstructure-based boundary element model is proposed for the large-scale thermal analysis of a spherical fuel element. This model presents detailed structural information of a large number of coated fuel particles dispersed in a spherical graphite matrix in order that temperature distributions at the level of fuel particles can be evaluated. The model is meshed with boundary elements in conjunction with the fast multipole method (FMM) in order that such large-scale computation is performed only in a personal desktop computer. Taking advantage of the fact that fuel particles are of the same shape, a similar sub-domain approach is used to establish the temperature translation mechanism between various layers of each fuel particle and to simplify the associated boundary element formulation. The numerical results demonstrate large-scale capacity of the proposed method for the multi-level temperature evaluation of the pebble-bed HTR fuel elements.

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