Long Deng¹, Xueying Huang^2,3,*, Heng Zuo⁴, Yuan Zheng², Chun Yang⁵, Yunhu Song¹, Dalin Tang⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 115-125, 2018, DOI: 10.31614/cmes.2018.04076

Abstract The mechanisms of systolic anterior motion (SAM) of the mitral valve in hypertrophic obstructive cardiomyopathy (HOCM) remain unclear. To investigate the angle of attack between blood flow and mitral valve leaflets at pre-SAM time point, patient-specific CT-based computational models were constructed for 5 patients receiving septal myectomy surgery to obtain pre- and post-operative 2D vector flow mapping. The comparisons between pre- and post-operative angles of attack based on 2D vector flow mapping of 5 patients were performed. It was found that there was no statistically significant difference between pre- and post-operative angles of attack (61.1±t wao vs. 56.2±56.o, p=0.306, n=5).… More >

Tianyu Wu¹, Wenliang Qiu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.1, pp. 47-66, 2018, DOI:10.3970/cmes.2018.115.047

Abstract The action of drifting ice floes may induce strong vibrations of offshore structures, and further reduce the structural safety and serviceability. The aim of this paper is to develop a method by considering ice crushing as a stochastic process. On the basis of ice force spectrum which considers the time and spatial correlation between the local ice forces, a simulation methodology to generate the stochastic ice forces process of vertical offshore structure is proposed. The crucial segment in the simulation is to accurately calculate the effective ice pressure, and it is accomplished by an empirical formula which can provide a… More >

H. T. Xiao^1,2,3, Y. Y. Xie^1,2, Z. Q. Yue⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.1, pp. 55-80, 2015, DOI:10.3970/cmes.2015.109.055

Abstract This paper examines the problem of a square-shaped crack embedded in a layered half-space whose external surface is subject to a uniform loading over a rectangular area. Two novel numerical methods and the superposition principle in fracture mechanics are employed for the analysis of the crack problem. The numerical methods are based on the fundamental solution of a multilayered elastic medium and are, respectively, applied to calculate the stress fields of layered halfspace without cracks and the discontinuous displacements of crack surfaces in layered halfspace. The stress intensity factor (SIF) values are calculated using discontinuous displacements and the influence of… More >

Vadim V. Romanuke¹

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.2, pp. 113-134, 2015, DOI:10.3970/cmes.2015.108.113

Abstract The problem of solving infinite noncooperative games approximately is considered. The game may either have solution or have no solution. The existing solution may be unknown as well. Therefore, an approach of obtaining the approximate solution of the infinite noncooperative game on the unit hypercube is suggested. The unit-hypercubic game isomorphism to compact infinite noncooperative games allows to disseminate the approximation approach on a pretty wide class of noncooperative games. The approximation intention is in converting the infinite game into a finite one, whose solution methods are easier rather than solving infinite games. The conversion starts with sampling the players’… More >

Essam Al-Bahkali^1,2, Hisham Elkenani¹, Souli Mhamed³

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.5, pp. 405-424, 2015, DOI:10.3970/cmes.2015.104.405

Abstract Simulation of airbag and membrane deployment under pressurized gas problems becomes more and more the focus of computational engineering, where FEM (Finite element Methods) for structural mechanics and Finite Volume for CFD are dominant. New formulations have been developed for FSI applications using mesh free methods as SPH method, (Smooth Particle Hydrodynamic). Up to these days very little has been done to compare different methods and assess which one would be more suitable. For small deformation, FEM Lagrangian formulation can solve structure interface and material boundary accurately, the main limitation of the formulation is high mesh distortion for large deformation… More >

E.F. Fontes Jr¹, J.A.F. Santiago¹, J.C.F. Telles¹

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.3, pp. 211-228, 2014, DOI:10.3970/cmes.2014.102.211

Abstract An iterative coupling procedure using different meshless methods is presented to solve linear elastic fracture mechanic (LEFM) problems. The domain of the problem is decomposed into two sub-domains, where each one is addressed using an appropriate meshless method. The method of fundamental solutions (MFS) based on the numerical Green’s function (NGF) procedure to generate the fundamental solution has been chosen for modeling embedded cracks in the elastic medium and the meshless local Petrov-Galerkin (MLPG) method has been chosen for modeling the remaining sub-domain. Each meshless method runs independently, coupled with an iterative update of interface variables to achieve the final… More >

M. Dehghan¹, M. Abbaszadeh², A. Mohebbi³

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.5, pp. 399-444, 2014, DOI:10.3970/cmes.2014.100.399

Abstract In this paper three numerical techniques are proposed for solving the system of N-coupled nonlinear Schrödinger (CNLS) equations. Firstly, we obtain a time discrete scheme by approximating the first-order time derivative via the forward finite difference formula, then for obtaining a full discretization scheme, we use the Kansa’s approach to approximate the spatial derivatives via radial basis functions (RBFs) collocation methodology. We introduce the moving least squares (MLS) approximation and radial point interpolation method (RPIM) with their shape functions, separately. It should be noted that the shape functions of RPIM unlike the shape functions of the MLS approximation have kronecker… More >

N. Pham-Sy¹, C.-D. Tran¹, N. Mai-Duy¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.5, pp. 363-397, 2014, DOI:10.3970/cmes.2014.100.363

Abstract In this paper, a high performance computing method based on the Integrated Radial Basis Function (IRBF), Control Volume (CV) and Domain Decomposition technique for solving Partial Differential Equations is presented. The goal is to develop an efficient parallel algorithm based on the Compact Local IRBF method using the CV approach, especially for problems with non-rectangular domain. The results showed that the goal is achieved as the computational efficiency is quite significant. For the case of square lid driven cavity problem with Renoylds number 100, super-linear speed-up is also achieved. The parallel algorithm is implemented in the Matlab environment using Parallel… More >

K. Luo¹, Y. L. Pi¹, W. Gao¹, M. A. Bradford¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.1, pp. 31-58, 2013, DOI:10.3970/cmes.2013.095.031

Abstract This paper presents a theoretical analysis for the time-dependent nonlinear behaviour and buckling of shallow concrete-filled steel tubular (CFST) arches under a sustained central concentrated load. The virtual work method is used to establish the differential equations of equilibrium for the time-dependent behaviour and buckling analyses of shallow CFST arches, and the age-adjusted effective modulus method is adopted to model the creep behaviour of the concrete core. Analytical solutions of time-dependent displacements and internal forces of shallow CFST arches are derived. It has been found that under a sustained central concentrated load, the deformations and bending moments in a shallow… More >

N. Pham-Sy¹, C.-D. Tran¹, T.-T. Hoang-Trieu¹, N. Mai-Duy¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.1, pp. 1-31, 2013, DOI:10.3970/cmes.2013.092.001

Abstract Compact Local Integrated Radial Basis Function (CLIRBF) methods based on Cartesian grids can be effective numerical methods for solving partial differential equations (PDEs) for fluid flow problems. The combination of the domain decomposition method and function approximation using CLIRBF methods yields an effective coarse-grained parallel processing approach. This approach has enabled not only each sub-domain in the original analysis domain to be discretised by a separate CLIRBF network but also compact local stencils to be independently treated. The present algorithm, namely parallel CLIRBF, achieves higher throughput in solving large scale problems by, firstly, parallel processing of sub-regions which constitute the… More >