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One of the major issues in the computational mechanics is to take into account the geometrical complexity. To overcome this difficulty and to avoid the expensive mesh generation, geometrically unfitted methods, i.e. the numerical methods…

Numerical Analysis · Mathematics 2021-10-12 Stephane Cotin , Michel Duprez , Vanessa Lleras , Alexei Lozinski , Killian Vuillemot

In this article we suggest two discretization methods based on isogeometric analysis (IGA) for planar linear elasticity. On the one hand, we apply the well-known ansatz of weakly imposed symmetry for the stress tensor and obtain a…

Numerical Analysis · Mathematics 2022-04-19 Jeremias Arf , Bernd Simeon

Materials with optimized band gap are needed in many specialized applications. In this work, we demonstrate that Hellmann-Feynman forces associated with the gap states can be used to find atomic coordinates with a desired electronic density…

Materials Science · Physics 2015-06-16 Kiran Prasai , Parthapratim Biswas , D. A. Drabold

Isogeometric analysis is a recently developed framework based on finite element analysis, where the simple building blocks in geometry and solution space are replaced by more complex and geometrically-oriented compounds. Box splines are an…

Numerical Analysis · Mathematics 2019-09-26 Tadej Kanduc , Carlotta Giannelli , Francesca Pelosi , Hendrik Speleers

In this paper, we discuss the application of the Generalized Finite Element Method (GFEM) to approximate the solutions of quasilinear elliptic equations with multiple interfaces in one dimensional space. The problem is characterized by…

Numerical Analysis · Mathematics 2021-02-02 Tilsa Aryeni , Quanling Deng , Victor Ginting

In this work, we aim to develop energy-stable parametric finite element approximations for a sharp-interface model with strong surface energy anisotropy, which is derived from the first variation of an energy functional composed of…

Numerical Analysis · Mathematics 2024-07-08 Meng Li , Chunjie Zhou

In this paper, we propose a geometrically nonlinear spectral shell element based on Reissner--Mindlin kinematics using a rotation-based formulation with additive update of the discrete nodal rotation vector. The formulation is provided in…

Numerical Analysis · Mathematics 2026-02-20 Nima Azizi , Wolfgang Dornisch

Independent component analysis (ICA) has proven useful for modeling brain and electroencephalographic (EEG) data. Here, we present a new, generalized method to better capture the dynamics of brain signals than previous ICA algorithms. We…

Quantitative Methods · Quantitative Biology 2007-05-23 Jorn Anemuller , Terrence J. Sejnowski , Scott Makeig

We present a review of the basic ideas and techniques of the spectral density functional theory which are currently used in electronic structure calculations of strongly-correlated materials where the one-electron description breaks down.…

Strongly Correlated Electrons · Physics 2009-11-11 G. Kotliar , S. Y. Savrasov , K. Haule , V. S. Oudovenko , O. Parcollet , C. A. Marianetti

An electrodynamic response of graphene to a strong electromagnetic radiation is considered. A hot electron model (HEM) is introduced and a corresponding system of nonlinear equations is formulated. Solutions of this system are found and…

Mesoscale and Nanoscale Physics · Physics 2019-09-18 S. A. Mikhailov

This paper discusses and analyses two domain decomposition approaches for electromagnetic problems that allow the combination of domains discretised by either N\'ed\'elec-type polynomial finite elements or spline-based isogeometric…

Computational Engineering, Finance, and Science · Computer Science 2019-01-04 Annalisa Buffa , Jacopo Corno , Carlo de Falco , Sebastian Schöps , Rafael Vázquez

In the present thesis, a computational framework for the analysis of the deformation and damage phenomena occurring at the micro-scale of polycrystalline materials is presented. Micro-mechanics studies are commonly performed using the…

Computational Engineering, Finance, and Science · Computer Science 2018-02-08 Vincenzo Gulizzi

Lattice mismatch in layered semiconductor structures with submicron length scales leads to extremely high nonuniform strains. This paper presents a finite element technique for incorporating the effects of the nonuniform strain into an…

Materials Science · Physics 2009-10-31 H. T. Johnson , L. B. Freund , C. D. Akyuz , A. Zaslavsky

Studying the electronic structure of defects in materials is an important subject in condensed matter physics. From a mathematical point of view, nonlinear mean-field models of localized defects in insulators are well understood. We present…

Mathematical Physics · Physics 2019-10-04 Éric Cancès , Ling-Ling Cao , Gabriel Stoltz

The true power of computational research typically can lay in either what it accomplishes or what it enables others to accomplish. In this work, both avenues are simultaneously embraced across several distinct efforts existing at three…

Materials Science · Physics 2024-11-06 Adam M. Krajewski

We investigate two unconditionally energy stable invariant energy quadratization (IEQ) finite element methods (FEMs) [Chen et al. Numerical Algorithms, DOI: 10.1007/s11075-024-01910-z, 2024] for solving the Cahn-Hilliard-Navier-Stokes…

Numerical Analysis · Mathematics 2026-04-24 Yaoyao Chen , Dongqian Li , Yin Yang , Peimeng Yin

The effect of higher order continuity in the solution field by using NURBS basis function in isogeometric analysis (IGA) is investigated for an efficient mixed finite element formulation for elastostatic beams. It is based on the Hu-Washizu…

Numerical Analysis · Mathematics 2023-09-08 Myung-Jin Choi , Roger A. Sauer , Sven Klinkel

We review our previous work on the dynamic structure factor S(k,omega) of liquid Ge (l-Ge) at temperature T = 1250 K, and of amorphous Ge (a-Ge) at T = 300 K, using ab initio molecular dynamics [Phys. Rev. B67, 104205 (2003)]. The…

Materials Science · Physics 2007-05-23 Jeng-Da Chai , D. Stroud

Electrical machines commonly consist of moving and stationary parts. The field simulation of such devices can be very demanding if the underlying numerical scheme is solely based on a domain discretization, such as in case of the Finite…

Computational Engineering, Finance, and Science · Computer Science 2017-09-18 Lars Kielhorn , Thomas Rüberg , Jürgen Zechner

In this article, we present a new unified finite element method (UFEM) for simulation of general Fluid-Structure interaction (FSI) which has the same generality and robustness as monolithic methods but is significantly more computationally…

Computational Engineering, Finance, and Science · Computer Science 2016-08-18 Yongxing Wang , Peter Jimack , Mark Walkley