A.E. Kampitsis¹, E.J. Sapountzakis²

CMES-Computer Modeling in Engineering & Sciences, Vol.103, No.6, pp. 367-409, 2014, DOI:10.3970/cmes.2014.103.367

Abstract In this paper a Boundary Element Method (BEM) is developed for the geometrically nonlinear inelastic analysis of Timoshenko beams of arbitrary doubly symmetric simply or multiply connected constant cross-section, resting on inelastic tensionless Winkler foundation. The beam is subjected to the combined action of arbitrarily distributed or concentrated transverse loading and bending moments in both directions as well as to axial loading, while its edges are subjected to the most general boundary conditions. To account for shear deformations, the concept of shear deformation coefficients is used. A displacement based formulation is developed and inelastic redistribution More >

S. Hamada¹

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.5, pp. 407-424, 2014, DOI:10.3970/cmes.2014.102.407

Abstract The voxel-based indirect boundary element method (IBEM) combined with the Laplace-kernel fast multipole method (FMM) is capable of analyzing relatively large-scale problems. A typical application of the IBEM is the electric field analysis in virtual-human models such as the model called Duke provided by the foundation for research on information technologies in society (IT’IS Foundation). An important property of voxel-version Duke models is that they have various voxel sizes but the same structural feature. This property is useful for examining the O(N) and O(D²) dependencies of the calculation times and the amount of memory required by More >

Vincenzo Mallardo¹, Eugenio Ruocco²

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.5, pp. 373-391, 2014, DOI:10.3970/cmes.2014.102.373

Abstract The NURBS based isogeometric analysis offers a novel integration between the CAD and the numerical structural analysis codes due to its superior capacity to describe accurately any complex geometry. Since it was proposed in 2005, the approach has attracted rapidly growing research interests and wide applications in the Finite Element context. Only recently, in 2012, it was successfully tested together with the Boundary Element Method. The combination of the isogeometric approach and the Boundary Element Method is efficient since both the NURBS geometrical representation and the Boundary Element Method deal with quantities entirely on the More >

R. Q. Rodríguez^1,2, C. L. Tan², P. Sollero¹, E. L. Albuquerque³

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.5, pp. 359-372, 2014, DOI:10.3970/cmes.2014.102.359

Abstract The efficient evaluation of the fundamental solution for 3D general anisotropic elasticity is a subject of great interest in the BEM community due to its mathematical complexity. Recently, Tan, Shiah, andWang (2013) have represented the algebraically explicit form of it developed by Ting and Lee (Ting and Lee, 1997; Lee, 2003) by a computational efficient double Fourier series. The Fourier coefficients are numerically evaluated only once for a specific material and are independent of the number of field points in the BEM analysis. This work deals with the application of hierarchical matrices and low rank More >

Jean-Philippe Jehl¹, Richard Kouitat Njiwa²

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.5, pp. 345-358, 2014, DOI:10.3970/cmes.2014.102.345

Abstract Extended continuum mechanical approaches are now becoming increasingly popular for modeling various types of microstructured materials such as foams and porous solids. The potential advantages of the microcontinuum approach are currently being investigated in the field of biomechanical modeling. In this field, conducting a numerical investigation of the material response is evidently of paramount importance. This study sought to investigate the potential of the (constrained) microstretch modeling method. The problem’s field equations have been solved by applying a numerical approach combining the conventional isotropic boundary elements method with local radial point interpolation. Our resulting numerical More >

Xiyong Huang¹, M. H. Aliabadi², Z. Sharif Khodaei³

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.4, pp. 291-330, 2014, DOI:10.3970/cmes.2014.102.291

Abstract In this paper, a stochastic dual boundary element formulation is presented for probabilistic analysis of fatigue crack growth. The method involves a direct differentiation approach for calculating boundary and fracture response derivatives with respect to random parameters. Total derivatives method is used to obtain the derivatives of fatigue parameters with respect to random parameters. First- Order Reliability Method (FORM) is applied to evaluate the most probable point (MPP). Opening mode fatigue crack growth problems are used as benchmarks to demonstrate the performance of the proposed method. More >

Y.C. Shiah¹, Chung-Lei Hsu¹, Chyanbin Hwu^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.4, pp. 257-270, 2014, DOI:10.3970/cmes.2014.102.257

Abstract As has been well documented for the boundary element method (BEM), a volume integral is present in the integral equation for thermoelastic analysis. Any attempt to directly integrate the integral shall inevitably involve internal discretization that will destroy the BEM’s distinctive notion as a true boundary solution technique. Among the schemes to overcome this difficulty, the exact transformation approach is the most elegant since neither further approximation nor internal treatments are involved. Such transformation for 2D anisotropic thermoelasticity has been achieved by Shiah and Tan (1999) with the aid of domain mapping. This paper revisits More >

L. Rodríguez-Tembleque¹, M.H. Aliabadi²

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.3, pp. 183-210, 2014, DOI:10.3970/cmes.2014.102.183

Abstract This work presents new contact constitutive laws for friction and wear modelling in fiber-reinforced plastics (FRP). These laws are incorporated to a numerical methodology which allows us to solve the contact problem taking into account the anisotropic tribological properties on the interfaces. This formulation uses the Boundary Element Method for computing the elastic influence coefficients. Furthermore, the formulation considers micromechanical models for FRP that also makes it possible to take into account the fiber orientation relative to the sliding direction, the fiber volume fraction, the aspect ratio of fibers, or the fiber arrangement. The proposed More >

Peng Weihong^1,2, Gao Feng¹, Cao Guohua³, Xu Yong², Cheng Hongmei¹

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.2, pp. 133-155, 2014, DOI:10.3970/cmes.2014.100.133

Abstract In this paper, the natural boundary element method is used to solve two-dimensional steady-state incompressible Stokes flows in a driven cavity. The analytical functions are expressed for the Stokes problem in an exterior circular domain under single value conditions, which satisfy the Stokes equations’ solutions in the form of complex functions. In order to obtain a uniform integral formula, the velocities on the boundary are expanded into Laurent series, and then compared with the analytical solutions obtained as described above. In this manner, the coefficients of the analytical solutions in the form of complex function… More >

J. Useche¹

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.2, pp. 105-118, 2014, DOI:10.3970/cmes.2014.100.105

Abstract In this work, the harmonic analysis of shallow shells using the Boundary Element Method, is presented. The proposed boundary element formulation is based on a direct time-domain integration using the elastostatic fundamental solutions for both in-plane elasticity and shear deformable plates. Shallow shell was modeled coupling boundary element formulation of shear deformable plate and two-dimensional plane stress elasticity. Effects of shear deformation and rotatory inertia were included in the formulation. Domain integrals related to inertial terms were treated using the Dual Reciprocity Boundary Element Method. Numerical examples are presented to demonstrate the efficiency and accuracy More >