Riitta Molarius¹, Pekka Tuomaala¹, Kalevi Piira¹, Minna Räikkönen¹, Christoph Aubrecht², Maria Polese³, Giulio Zuccaro^3,4, KaroliinaPilli-Sihvola⁵, Kalev Ranna

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.2, pp. 131-158, 2015, DOI:10.3970/cmes.2015.109.131

Abstract In northern regions, society can be seriously interrupted by a prolonged electricity network blackout due to a winter storm that cuts off power, communication and road networks. Due to hard winter weather it is essential to enhance the resilience of society to avoid danger to life. This can be achieved by developing new models to enhance preparedness for coming disaster events and to support rescue and other authorities to focus their resources on the most vulnerable targets in actual cases of emergencies. This paper presents a part of the results of activities performed within the EU project ‘CRISMA – Modelling… More >

Y. T. Wu¹, Y. F. Nie², Z. H. Yang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.4, pp. 297-325, 2014, DOI:10.3970/cmes.2014.099.297

Abstract Four representative multiscale methods, namely asymptotic homogenization method (AHM), heterogeneous multiscale method (HMM), variational multiscale (VMS) method and multiscale finite element method (MsFEM), for elliptic problems with multiscale coefficients are surveyed. According to the features they possess, these methods are divided into two categories. AHM and HMM belong to the up–down framework. The feature of the framework is that the macroscopic solution is solved first with the help of effective information computed in local domains, and then the multiscale solution is resolved in local domains using the macroscopic solution when necessary. VMS method andMsFEM fall in the uncoupling framework. The… More >

T.I. Zohdi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.3, pp. 261-277, 2014, DOI:10.32604/cmes.2014.098.261

Abstract A widespread use of lasers is for the ablation of biological tissue, in particular for dermal applications involving the removal of cancerous tissue, skin spots, aged skin and wrinkles. For a laser to ablate tissue, the power intensity must be sufficiently high to induce vaporization/burning of the target material. However, if performed improperly, the process can cause excessive microscale thermal injuries to surrounding healthy tissue. This motivates the present work, which attempts to develop and assemble simple models for the primary heat transfer mechanisms that occur during the process. First, in order to qualitatively understand the system, the terms that… More >

Shengzhong Li¹, Feng Zhao¹, Qi-Jun Ni¹

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.2, pp. 123-149, 2013, DOI:10.3970/cmes.2013.092.123

Abstract With the rapid development of computer technology and the continuous improvement of optimization theory, optimization techniques have been introduced into the field of ship design. Optimization algorithms and advanced CFD techniques are successfully integrated together into what is known as Simulation- Based Design (SBD) techniques, which opens a new situation for hull-form optimization design and configuration innovation. In this paper, fundamental elements of the SBD techniques are described and crucial components are analyzed profoundly. Focus is on breaking through key technologies as hull geometry modification and reconstruction, global optimization algorithms, and codes integration. Combined with high-fidelity CFD codes (on RANS),… More >

Li-Tien Cheng²³, Myungjoo Kang⁴, Stanley Osher⁴, Hyeseon Shim⁴, Yen-Hsi Tsai⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 347-360, 2004, DOI:10.3970/cmes.2004.005.347

Abstract Geometric optics makes its impact both in mathematics and real world applications related to ray tracing, migration, and tomography. Of special importance in these problems are the wavefronts, or points of constant traveltime away from sources, in the medium. Previously in [Osher, Cheng, Kang, Shim, and Tsai(2002)], we initiated a level set approach for the construction of wavefronts in isotropic media that handled the two major algorithmic issues involved with this problem: resolution and multivalued solutions. This approach was quite general and we were able to construct wavefronts in the presence of refraction, reflection, higher dimensions, and, in [Qian, Cheng,… More >

P. Castillo², J. Koning³, R. Rieben⁴, D. White⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 331-346, 2004, DOI:10.3970/cmes.2004.005.331

Abstract In this article, we present a computational framework for solving problems arising in electromagnetism. The framework is derived from a modern geometrical approach and is based on differential forms (or p-forms). These geometrical entities provide a natural framework for modeling of physical quantities such as electric potentials, electric and magnetic fields, electric and magnetic fluxes, etc. We have implemented an object oriented class library, called FEMSTER. The library is designed for high order finite element approximations. In addition, it can be expanded by including user-defined data types or by deriving new classes. Finally, the versatility of the software is shown… More >

Z. T. Ma¹, X. Zhang^1,2, P. Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.55, No.1, pp. 61-88, 2010, DOI:10.3970/cmes.2010.055.061

Abstract The Material Point Method (MPM) is more expensive in terms of storage than other methods, as MPM makes use of both mesh and particle data. Therefore, it is critical to develop an efficient MPM framework for engineering applications, such as impact and explosive simulations. This paper presents a new architecture for MPM computer code, developed using object-oriented design, which enables MPM analysis of a mass of grains, large deformation, high strain rates and complex material behavior. It is flexible, extendible, and easily modified for a variety of MPM analysis procedures. An MPM scheme combining contact algorithm with USF, USL and… More >

G. Desmeulles, S. Bonneaud, P. Redou>, V. Rodin, J. Tisseau

CMES-Computer Modeling in Engineering & Sciences, Vol.47, No.3, pp. 299-330, 2009, DOI:10.3970/cmes.2009.047.299

Abstract Virtual reality can enable computer scientists and domain experts to perform in virtuo experiments of numerical models of complex systems. Such dynamical and interactive experiments are indeed needed when it comes to complex systems with complex dynamics and structures. In this context, the question of the modeling tool to study such models is crucial. Such tool, called a virtuoscope, must enable the virtual experimentation of models inside a conceptual and experimental framework for imagining, modeling and experimenting the complexity of the studied systems. This article describes a conceptual framework and a meta model, called RéISCOP, that enable the construction and… More >

Gang Lin¹, Yinghua Liu^1,2, Zhihai Xiang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.47, No.3, pp. 217-252, 2009, DOI:10.3970/cmes.2009.047.217

Abstract Deterioration of reinforced concrete (RC) structures due to chloride ingress followed by reinforcement corrosion is a serious problem all over the world, therefore prediction of chloride profiles is a key element in evaluating durability and integrity of RC structures exposed to chloride environment. In the present paper, an integrated finite element-based computational framework is developed for predicting service life of RC structures exposed to chloride environment, which takes environment temperature and humidity fluctuations, diffusion and convection, chloride binding, as well as the decay of durability of structures caused by coupled deterioration processes into account. The decay of RC structures due… More >

R.Kanapady¹, K.K.Tamma²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.1, pp. 103-118, 2003, DOI:10.3970/cmes.2003.004.103

Abstract Of general interest here is the time dimension aspect wherein discretized operators in time may be continuous or discontinuous; and of particular interest and focus here is the design of time discretized operators in the context of discontinuous state-phase for computational dynamics applications. Based on a generalized bi-discontinuous time weighted residual formulation, the design leading to a new unified set of hierarchical energy conserving and energy dissipating time discretized operators are developed for the first time that are fundamentally useful for time adaptive computations for dynamic problems. Unlike time discontinuous Galerkin approaches, the design is based upon a time discontinuous… More >