K. Kuramoto¹, M. Furuichi², K. Kakuda²

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.3, pp. 169-186, 2015, DOI:10.3970/cmes.2015.106.169

Abstract This paper describes a scheme to improve efficiency of multi-agent simulation system (MAS) on single computer that has multiple processor cores. Simulation technology is applied for broad usage in the world, and MAS gathers attention from the fields that treat complicated and non-numeric issues such as traffic analysis, analyzing evacuation from a building, and defense training. Since the requirements of simulation scale and fidelity are growing, the importance of their performance is also increasing. However, CPU clock speedup is slowing, and improvement of computer performance has come to depend on the number of processors, cores, and graphics processing units. Consequently,… More >

Hai-Kun Wang^1,2, Robert Haynes³, Hong-Zhong Huang¹, Leiting Dong^2,4, Satya N. Atluri²

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.1, pp. 1-24, 2015, DOI:10.3970/cmes.2015.105.001

Abstract In this paper, we propose an approach for diagnostics and prognostics of damaged aircraft structures, by combing high-performance fatigue mechanics with filtering theories. Fast & accurate deterministic analyses of fatigue crack propagations are carried out, by using the Finite Element Alternating Method (FEAM) for computing SIFs, and by using the newly developed Moving Least Squares (MLS) law for computing fatigue crack growth rates. Such algorithms for simulating fatigue crack propagations are embedded in the computer program Safe- Flaw, which is called upon as a subroutine within the probabilistic framework of filter theories. Both the extended Kalman as well as particle… More >

R.H. Haney¹, R.V. Mohan²

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.5, pp. 431-452, 2013, DOI:10.3970/cmes.2013.095.431

Abstract The use of Graphics Processing Units (GPUs) as co-processors for single CPU/GPU computing systems has become pronounced in high performance computing research, however the solution of truly large scale computationally intensive problems require the utilization of multiple computing nodes. Multiple CPU/GPU computing systems bring new complexities to the observed performance of computationally intensive applications, the more salient of which is the cost of local CPU-GPU host and intra-nodal communication. This paper compares and analyzes the performance of a computationally intensive application represented by resin infusion flow during liquid composite molding process for the manufacture of structural composites application via two… More >

Zhiqiang Yang¹, Junzhi Cui², Yufeng Nie¹, Qiang Ma²

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.5, pp. 419-442, 2012, DOI:10.3970/cmes.2012.088.419

Abstract In this paper, a new second-order two-scale (SOTS) method is developed to predict heat transfer performances of periodic porous materials with interior surface radiation. Firstly, the second-order two-scale formulation for computing temperature field of the problem is given by means of construction way. Then, the error estimation of the second-order two-scale approximate solution is derived on some regularity hypothesis. Finally, the corresponding finite element algorithms are proposed and some numerical results are presented. They show that the SOTS method in this paper is feasible and valid for predicting the heat transfer performances of periodic porous materials. More >

E. Mesquita¹, J.Labaki ¹ and L.O.S.Ferreira¹

CMES-Computer Modeling in Engineering & Sciences, Vol.51, No.2, pp. 143-168, 2009, DOI:10.3970/cmes.2009.051.143

Abstract There is a growing trend towards solving problems of computational mechanics by parallelization strategies. The traditional approach is to implement the parallelization procedures on CPUs based on the MPI or OpenMP paradigms. Recent efforts have been made to implement computational tasks on general-purpose programmable graphics hardware (GPGPU). The GPU is specially well-suited to address problems that can be formulated in form of data-parallel computations with high arithmetic intensity. This work addresses the implementation of the Longman's integration method on graphics hardware. A serial implementation of Longman's method was rewritten under the SIMD (Single Input Multiple Data) parallel programming paradigm. The… More >

S. Chantasiriwan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.3, pp. 137-146, 2006, DOI:10.3970/cmes.2006.015.137

Abstract The multiquadric collocation method is the collocation method based on radial basis function known as multiquadrics. It has been successfully used to solve several linear and nonlinear problems. Although fluid flow problems are among problems previously solved by this method, there is still an outstanding issue regarding the influence of the free parameter of multiquadrics (or the shape parameter) on the performance of the method. This paper provides additional results of using the multiquadric collocation method to solve the lid-driven cavity flow problem. The method is used to solve the problem in the stream function-vorticity formulation and the velocity-vorticity formulation.… More >

Wanil Byun¹, Seung Jo Kim²

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.6, pp. 551-576, 2012, DOI:10.3970/cmes.2012.086.551

Abstract A structural eigensolver for large-scale finite element analysis is developed. The algorithms and data structures implemented in this paper are well suited for a distributed memory environment. As an eigenvalue extracting algorithm, the well-known M orthogonal block Lanczos iteration incorporated with a parallel multifrontal solver (PMFS) was chosen. Basically, for the better performance of this algorithm in parallel computation, Lanczos vector allocation, mass matrix multiplication, and M inner product procedures were efficiently implemented. And the PMFS for a linear equation which is the most time-consuming part during Lanczos iterations was improved. The idea was to optimize network topologies of parallel… More >

P. L. Bishay¹, S.N. Atluri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.1, pp. 41-98, 2012, DOI:10.3970/cmes.2012.084.041

Abstract Higher-order two-dimensional as well as low and higher-order three-dimensional new Hybrid/Mixed (H/M) finite elements based on independently assumed displacement, and judiciously chosen strain fields, denoted by HMFEM-2, are developed here for applications in macro-mechanics. The idea of these new H/M finite elements is based on collocating the components of the independent strain field, with those derived from the independently assumed displacement fields at judiciously and cleverly chosen collocation points inside the element. This is unlike the other techniques used in older H/M finite elements where a two-field variational principle was used in order to enforce both equilibrium and compatibility conditions… More >

Sheng Yan Li¹, Bin Gang Xu^1,2, Xiao Ming Tao¹, Hong Hu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.1, pp. 33-56, 2011, DOI:10.3970/cmes.2011.077.033

Abstract Slender yarn structure made from natural fibers, nano-fibers, carbon nanotubes or other types of fibrous materials is all formed by twisting an assembly of short or long fibers and its performance is significantly influenced by the physical behavior of these fibers in the slender yarn forming region - a small triangle area called spinning triangle. In this paper, a new generalized FEM model of spinning triangle has been developed to theoretically analyze the fiber structural and mechanical performance in fabrication of these slender yarn structures. In this proposed model, a geometrical model of spinning triangle is developed and the initial… More >

Jong Keun Moon¹, Seung Jo Kim²

CMES-Computer Modeling in Engineering & Sciences, Vol.67, No.3, pp. 239-264, 2010, DOI:10.3970/cmes.2010.067.239

Abstract Large structural problems with high precision and complexity require a high-performance computation using the efficient parallel algorithm. The purpose of this paper is to present the parallel performance of thermal-structural coupled analysis tested on a parallel cluster system. In the coupled analysis, the heat transfer analysis is carried out, and then the structural analysis is performed based on temperature distribution. For the automatic and efficient connection of two parallel analysis modules, the several communication patterns were studied. The parallel performance was demonstrated for the sample and the real application problems, such as a laminated composite material by the DNS(Direct Numerical… More >