Delfim Soares Jr. ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.50, No.2, pp. 97-114, 2009, DOI:10.3970/cmes.2009.050.097

Abstract In this work, meshless methods based on the local Petrov-Galerkin (MLPG) approach are presented to analyse electromagnetic wave propagation problems. Formulations adopting the Heaviside step function and the Gaussian weight function as the test functions in the local weak form are considered. The moving least square (MLS) method is used to approximate the physical quantities in the local integral equations. After spatial discretization is carried out, a system of ordinary differential equations of second order is obtained. This system is solved in the time-domain by the Houbolt's method, allowing the computation of the so-called primary fields (either the electric or… More >

J. M. García-Aznar^1,2, M. A. Pérez^1,2, P. Moreo^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.3, pp. 271-302, 2009, DOI:10.3970/cmes.2009.048.271

Abstract There are many interfaces between biological materials with a structural functionality, where their mechanical behaviour is crucial for their own performance. Advanced tools such as cohesive surface models are being used to simulate the failure and degradation of this kind of biological interactions. The goal of this paper, in a first step, is to present some cohesive surface models that include damage and repair in interfaces and its application to different biomechanical problems. Secondly, we discuss about the main challenges that we have to improve in the modelling of interfaces for a mechanobiological approach. More >

Delfim Soares Jr.¹

CMES-Computer Modeling in Engineering & Sciences, Vol.44, No.2, pp. 157-176, 2009, DOI:10.3970/cmes.2009.044.157

Abstract The numerical modelling of electromagnetic waves by finite element - boundary element coupling procedures is discussed here, taking into account time-domain approaches. In this study, the global model is divided into different sub-domains and each sub-domain is analysed independently and explicitly at each time-step of the analysis: the interaction between the different sub-domains of the global model is accomplished by interface procedures. A multi-level time-step algorithm is considered in order to improve the flexibility, accuracy and stability (especially when conditionally stable time-marching procedures are employed) of the coupled analysis. At the end of the paper, numerical examples are presented, illustrating… More >

E. Brusa¹, E. Franceschinis², S. Morsut²

CMES-Computer Modeling in Engineering & Sciences, Vol.42, No.2, pp. 75-106, 2009, DOI:10.3970/cmes.2009.042.075

Abstract Electrodes motion and positioning are critical issues of the Electric Arc Furnace (EAF) operation in steelmaking process. During the melting process electrode is exposed to some impulsive and harmonic forces, superimposing to the structure's static loading. Unfortunately, structural vibration may interact with the electric arc regulation, because of the dynamic resonance. Instability in the furnace power supplying and dangerous electrode breakage may occur as a consequence of those dynamic effects. In this paper the dynamic behaviour of a real EAF structure is discussed and some numerical models are proposed. Available experimental data, collected by a monitoring system on a real… More >

G. Haasemann¹, M. Kästner², V. Ulbricht³

CMES-Computer Modeling in Engineering & Sciences, Vol.42, No.1, pp. 35-58, 2009, DOI:10.3970/cmes.2009.042.035

Abstract The purpose of this paper is the presentation of a new efficient modelling strategy based on the combination of Binary Model and Extended Finite Element Method (X-FEM). It is applied to represent the internal architecture of textile reinforced composites where the resin-saturated fabric is characterised by a complex geometry. Homogenisation methods are used to compute the effective elastic material properties. Thereby, the discrete formulation of periodic boundary conditions is adapted regarding additional degrees of freedom used by finite elements which are based on the X-FEM. Finally, the results in terms of effective material properties reveal a good agreement with parameters… More >

Patrícia C.T. Gonçalves^1,2, João Manuel R.S. Tavares^1,2, R.M. Natal Jorge^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.32, No.1, pp. 45-56, 2008, DOI:10.3970/cmes.2008.032.045

Abstract The main goals of the present work are to automatically extract the contour of an object and to simulate its deformation using a physical approach. In this work, to segment an object represented in an image, an initial contour is manually defined for it that will then automatically evolve until it reaches the border of the desired object. In this approach, the contour is modelled by a physical formulation using the finite element method, and its temporal evolution to the desired final contour is driven by internal and external forces. The internal forces are defined by the intrinsic characteristics of… More >

H.K. Mebatsion^1,2, P. Verboven¹, P. T. Jancsók¹, Q.T. Ho¹, B.E. Verlinden³, B.M. Nicolaï^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.29, No.3, pp. 137-150, 2008, DOI:10.3970/cmes.2008.029.137

Abstract Transport processes of gas and moisture are among the most important physiological processes in plant tissue. Microscale transport models based on Navier-Stokes equations provide insight into such processes at the microscopic scale. Due to microscopic complexity, numerical solutions based on the finite element or finite volume methods are mandatory. Therefore, a 3D geometric model of the tissue is essential. In this article, a novel algorithm for geometric reconstruction of 2D slices of synchrotron tomographic images is presented. The boundaries of 2D cells on individual slices were digitized to establish a set of boundary coordinates and the slice index of individual… More >

RaviS Nanjundiah¹

CMES-Computer Modeling in Engineering & Sciences, Vol.27, No.1&2, pp. 1-24, 2008, DOI:10.3970/cmes.2008.027.001

Abstract In this paper, application of high performance computing to climate modelling with specific reference to global General Circulation Models (GCM) is discussed. Methods of parallelization of global atmospheric models based on their numerical schemes is presented. It is seen that there is an interesting co-evolution of computer architecture and the type of numerical schemes used in general circulation models. A detailed survey of the Indian HPC scenario for meteorological computing is presented. Innovative and pioneering aspects of Indian efforts are highlighted. More >

A. Arockiarajan¹, A. Menzel²

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.1, pp. 55-72, 2007, DOI:10.3970/cmes.2007.020.055

Abstract To study rate-dependent properties of piezoelectric materials a micro-mechanically motivated model is applied in this work. The developed framework is embedded into a coupled three-dimensional finite element setting, whereby each element is assumed to represent one grain and, moreover, possesses a random initialisation of the underlying polarisation direction. Furthermore, an energy-based criterion is used for the initiation of the onset of domain switching and the subsequent propagation of domain wall motion during the switching process is modelled via a linear kinetics theory. The interaction between individual grains is thereby incorporated by means of a probabilistic approach -- a purely phenomenologically… More >

A. Arockiarajan¹, A. Menzel²

CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.2, pp. 163-178, 2007, DOI:10.3970/cmes.2007.019.163

Abstract To study rate-dependent properties of piezoelectric materials a micro-mechanically motivated model is applied in this work. The developed framework is embedded into a coupled three-dimensional finite element setting, whereby each element is assumed to represent one grain and, moreover, possesses a random initialisation of the underlying polarisation direction. Furthermore, an energy-based criterion is used for the initiation of the onset of domain switching and the subsequent propagation of domain wall motion during the switching process is modelled via a linear kinetics theory. The interaction between individual grains is thereby incorporated by means of a probabilistic approach -- a purely phenomenologically… More >