I. Smojver¹, D. Ivancevic¹, D. Mihaljevic²

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.2, pp. 191-216, 2010, DOI:10.3970/cmes.2010.070.191

Abstract This paper tackles the problem of numerical prediction of bird strike induced damage in real aeronautical structures using highly detailed finite element models and modern numerical approaches. Due to the complexity of today's aeronautical structures, numerical damage prediction methods have to be able to take into account various failure and degradation models of different materials. The work presented in this paper is focused on damage modeling in metallic items of aeronautical structures.
Abaqus/Explicit has been employed to perform geometrical and material nonlinear transient dynamic analyses. The problem of soft body impacts has been tackled by applying… More >

W. Pietraszkiewicz¹

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.2, pp. 153-190, 2010, DOI:10.3970/cmes.2010.070.153

Abstract Chien Wei-Zhang (1944) derived three equilibrium equations and three compatibility conditions of the nonlinear theory of thin, isotropic elastic shells entirely in terms of the surface stress and strain measures associated with the shell base surface. This allowed Him to divide the complex boundary value problem (BVP) of nonlinear shell analysis into two disjoint and supposedly simpler steps: I) finding the surface stress and strain measures from the intrinsic BVP, and II) establishing position in space of the deformed base surface from already known surface strain measures. In the present paper some achievements of this… More >

Qiao Wang¹, Yu Miao^1,2, Junjie Zheng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.2, pp. 123-152, 2010, DOI:10.3970/cmes.2010.070.123

Abstract In this paper, a fast formulation of the hybrid boundary node method (Hybrid BNM) for solving 3D elasticity is presented. Coupling modified variational principle with the Moving Least Squares (MLS) approximation, the Hybrid BNM only requires discrete nodes constructed on the surface of a domain. The preconditioned GMERS is employed to solve the resulting system of equations. At each iteration step of the GMERS, the matrix-vector multiplication is accelerated by the fast multipole method (FMM). The fundamental solution of three-dimensional elasticity problem is expanded in terms of series. An oct-tree data structure is adopted to More >

S. D. Akbarov^1,2, C. Ipek³

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.2, pp. 93-122, 2010, DOI:10.3970/cmes.2010.070.093

Abstract This paper studies the influence of the imperfectness of the interface conditions on the dispersion of the axisymmetric longitudinal waves in the pre-strained compound cylinder. The investigations are made within the framework of the piecewise homogeneous body model by utilizing the 3D linearized theory of elastic waves in elastic bodies with initial stresses. It is assumed that the layers of the compound cylinder are made from high elastic compressible materials and their elasticity relations are given through the harmonic potential. The shear spring type imperfectness of the interface conditions is considered and the degree of More >

Wei-Xin Ren^1,2,3, Cong-Cong Su¹, Wang-Ji Yan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.1, pp. 67-92, 2010, DOI:10.3970/cmes.2010.070.067

Abstract A beam-arch segment assembly procedure is presented in this paper for the dynamic modelling and analysis of arch bridges. Such a beam-arch segment assembly is composed of different structural elements of arch bridges such as arch ribs (curved beams), suspenders, girders and floor beams. Based on the energy principle in structural dynamics, the stiffness matrix and mass matrix of such an assembly are formulated. The proposed procedure is then implemented to carry out the free vibration analysis of the Jian concrete filled tubular arch bridge. It is demonstrated that the proposed beam-arch segment assembly procedure More >

V. Lemiale^1,2, J. Nairn³, A. Hurmane¹

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.1, pp. 41-66, 2010, DOI:10.3970/cmes.2010.070.041

Abstract We assessed the suitability of the Material Point Method (MPM) to simulate the equal channel angular pressing technique (ECAP). This severe plastic deformation process combines several interesting and challenging features in the context of numerical simulations, namely large displacements, large plastic deformations, as well as abrupt contact changes between the rigid tools and the work piece. Moreover, ECAP has been intensively studied, experimentally, numerically and theoretically, which makes it an ideal benchmark for testing MPM. Results from finite element analysis are also presented for comparison to MPM because this method is widely considered as a More >

P. Redou¹, L. Gaubert¹, G. Desmeulles¹, P-A. Béal², C. Le Gal², V. Rodin³

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.1, pp. 11-40, 2010, DOI:10.3970/cmes.2010.070.011

Abstract Multi Interaction Systems, used in the context of Virtual Reality, are dedicated to real-time interactive simulations. They open the way to the in virtuo experimentation, especially useful in the domain of biochemical kinetics. To this purpose, chaotic and asynchronous scheduling of autonomous processes is based upon desynchronization of phenomena involved in the system. It permits interactivity, especially the capability to add or remove phenomena in the course of a simulation. It provides methods of resolution of ordinary differential systems and partial derivative equations. Proofs of convergence for these methods have been established, but the problem of More >

Şahin Emrah Amrahov¹, Iman N.Askerzade¹

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.1, pp. 1-10, 2010, DOI:10.3970/cmes.2010.070.001

Abstract In this paper we define multivariable fuzzy functions (MFF) and corresponding multivariable crisp functions (MCF). Then we give a definition for the maximum value of MFF, which in some cases coincides with the maximum value in Pareto sense. We introduce generalized maximizing and minimizing sets in order to determine the maximum values of MFF. By equating membership functions of a given fuzzy domain set and the corresponding maximizing set, we obtain a curve of equal possibilities. Then we use the method of Lagrange multipliers to solve the resulting nonlinear optimization problem when the membership functions More >

K. Kakuda¹, A. Seki¹, Y. Yamauchi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.69, No.3, pp. 281-306, 2010, DOI:10.3970/cmes.2010.069.281

Abstract A finite element scheme based on the concept of TVD (total variation diminishing) with a flux-limiter for the hyperbolic systems of conservation laws is presented. The numerical flux is formulated effectively by the weighted integral form using exponential weighting functions. The TVD finite element scheme is applied to a Riemann problem, namely the shock-tube problem, for the Euler system of equations. Numerical results demonstrate the workability and the validity of the present approach through comparison with the exact solutions. More >

Adan Vega, Naoki Osawa, Sherif Rashed, Hidekazu Murakawa

CMES-Computer Modeling in Engineering & Sciences, Vol.69, No.3, pp. 261-280, 2010, DOI:10.3970/cmes.2010.069.261

Abstract A three dimensional thermal-elasto-plastic FEA has been performed to predict the heat induced (inherent) deformation produced in thick steel plates formed by line heating. Using this FEA, the edge effect on inherent deformation is clarified. From the results of this study, a method to predict the edge effect is developed. Using this method, the edge effect on inherent deformation, for a wide range of plate thickness and heating condition, can be easily predicted, been this, an important step toward the automation of the process. More >