Min Ki Kim¹, Seung Jo Kim²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.2, pp. 52-52, 2009, DOI:10.3970/icces.2009.012.052

Abstract A new concept of hybrid iterative-multifrontal linear solution method is presented for large scale structural analysis problems. Multifrontal solution method is the best direct solution method ever known, so it is adequate for Domain decompostion types of iterative solvers. Multifrontal solver is served as an internal subdomain solver for domain decomposition iterative solver for achieving high performance of domain decomposition iterative solver. Lagrange multiplier is introduced to enforce the continuity of interface between subdomains. And corner DOF is introduced to avoid singularities of subdomains. Hybrid solution method is expected to show good parallel performance for More >

Raimund Rolfes, Matthias Vogler, Benedikt Kriegesmann¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.2, pp. 43-44, 2009, DOI:10.3970/icces.2009.012.043

Abstract Fiber composite structures are usually thin-walled and hence, prone to buckling. Thus, beside material failure also stability problems have to be considered.

Thin-walled cylindrical composite shells buckle in the elastic region and thus, there is no need to consider material non-linearities or material failure. Never the less, a robust design guide for composite shells does not exist until today. The most frequently guideline is NASA SP-8007, which gives an empirical based knockdown factor. Because this guideline is not intended for composite shells and it turned out to be very conservative in numerous cases several approaches… More >

Yangkyun kim¹, Sungcho Kim², Jongwook Choi², Jeong Soo Kim²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.4, pp. 123-124, 2009, DOI:10.3970/icces.2009.011.123

Abstract This paper analyzes computationally the flow field for the full geometry model of a commercial passenger airplane, Boeing747-400. The geometric dimension of an airplane was acquired by means of the reverse engineering technique adopting the photo scanning measurement. The steady three-dimensional viscous compressible flow field was calculated when the airplane cruises under side flow. The basic computational conditions were considered as the same to those of Boeing 747-400's cruising state, i.e., the atmospheric condition at 13 km above the sea level and Mach number of 0.85. The boundary conditions are the same that the freestream… More >

C.-L. Kuo, C.-S. Liu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.3, pp. 85-86, 2009, DOI:10.3970/icces.2009.011.085

Abstract In this paper, the inverse problems in a multiply connected domain governed by the Laplace equation have been investigated numerically by the developed moving modified Trefftz method. When solving the direct Laplace problem with the conventional Trefftz method, one may treat the ill-posed linear algebraic equations because the solution is obtained by expanding the diverging series; while when the inverse Laplace problem is encountered, it is more difficult to treat the more seriously ill-posed behaviors because the incomplete boundary data, and its solution, if exists, does not depend on the given boundary data continuously. Even… More >

A.S. Koyuncugil¹, N. Ozgulbas²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.2, pp. 39-46, 2009, DOI:10.3970/icces.2009.011.039

Abstract In this paper, a data mining model for detecting financial and operational risk indicators by CHAID Decision Tree is presenting. The identification of the risk factors by clarifying the relationship between the variables defines the discovery of knowledge from the financial and operational variables. Automatic and estimation oriented information discovery process coincides the definition of data mining. During the formation of model; an easy to understand, easy to interpret and easy to apply utilitarian model that is far from the requirement of theoretical background is targeted by the discovery of the implicit relationships between the More >

Alaimo A.¹, Milazzo A.¹, Orlando C.¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.1, pp. 9-16, 2009, DOI:10.3970/icces.2009.011.009

Abstract The main target of the present paper is the analysis of the fracture mechanics behavior of delaminated composite structures actively repaired through piezoelectric patches. The aim at issue has been achieved by using a boundary element code implemented to study piezoelectric solids, including, as limiting case, the applicability to linear elastic anisotropic materials. The assembled structures, made up of the damaged composite components and the piezoelectric patches, have been modeled through the multidomain technique. To take into account for the adhesive layer among the host structure and the active patch, an interface spring-model has been More >

Zone-Ching Lin¹, Ming-Long Huang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.3, pp. 89-90, 2009, DOI:10.3970/icces.2009.010.089

Abstract The paper develops a two dimensional quasi-steady molecular staic model to simulate the vertical down press copper workpiece by down press the nanoscale depth of abrasive grains in different shapes. The research of the down pressing copper workpiece of abrasive grains in this paper uses the hexagonal close packed diamond abrasive grains to down press the perfect face-centered cubic copper. The paper's simulation of down pressing nanoscale depth model of abrasive grain by two dimensional quasi-steady molecular statics model is a step by step to down press copper workpiece by diamond abrasive grain. It is… More >

Tei-Chen Chen^1,2, Heng-Chieh Wang¹, Shu-Fan Wu¹, Yen-Hung Lin¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.4, pp. 247-262, 2009, DOI:10.3970/icces.2009.009.247

Abstract Mechanical properties of materials in the micro- and nano-meter scale have been successfully obtained by using the indentation technique. Up to now, large-scale atomistic models to simulate the experimental condition, however, still remain computationally demanding. In this article, a simple and accurate method is proposed to derive the intermolecular potential functions of coarse-grained molecular dynamics (CGMD) suitable for various single crystalline materials. This CGMD technique is then provided to simulate nano-indentation process to verify its accuracy and reliability. Simulation results evaluated by CGMD approach are obtained and compared to those predicted by MD. It is More >

Takéhiko Nakama¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.4, pp. 233-242, 2009, DOI:10.3970/icces.2009.009.233

Abstract Random noise perturbs objective functions in a variety of practical optimization problems, and genetic algorithms (GAs) have been widely proposed as an effective optimization tool for dealing with noisy objective functions. In this paper, we investigate GAs applied to objective functions that are perturbed by multiple sources of additive and multiplicative noise that each take on finitely many values. We reveal the convergence properties of GAs by constructing and analyzing a Markov chain that explicitly models the evolution of the algorithms in noisy environments. Our analysis shows that this Markov chain is indecomposable; it has… More >

Sergei Alexandrov¹, Mustafa Yusof²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.1, pp. 11-24, 2009, DOI:10.3970/icces.2009.010.011

Abstract An efficient method for quick analysis and design of a class of metal forming processes is proposed. The method is based on the upper bound theorem and deals with continued deformation. Its main advantage is that numerical minimization involved in the upper bound method and solving differential equations for updating the configuration of deforming material are uncoupled. It significantly reduces computation time. Even though the accuracy of the method is unknown in advance, a procedure for verifying its accuracy a posteriori is proposed. The method is applied to plane strain compression of a viscous layer More >