Sökning: "finite elements analysis"

Visar resultat 1 - 5 av 161 avhandlingar innehållade orden finite elements analysis.

  1. 1. Approximating Stochastic Partial Differential Equations with Finite Elements: Computation and Analysis

    Författare :Andreas Petersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Lévy process; Lyapunov equation; white noise; finite element method; multilevel Monte Carlo; Monte Carlo; multiplicative noise; asymptotic mean square stability; stochastic heat equation; covariance operator; weak convergence; generalized Wiener process; numerical approximation; stochastic wave equation; Stochastic partial differential equations;

    Sammanfattning : Stochastic partial differential equations (SPDE) must be approximated in space and time to allow for the simulation of their solutions. In this thesis fully discrete approximations of such equations are considered, with an emphasis on finite element methods combined with rational semigroup approximations. LÄS MER

  3. 2. The application of edge elements in electromagnetics

    Författare :Thomas Rylander; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite-differences time-domain; stability analysis; NASA almond; finite element method; edge elements; scattering; mass lumping;

    Sammanfattning : .... LÄS MER

  4. 3. A hybrid finite element method for electromagnetics with applications in time-domain

    Författare :DAVID DEGERFELDT; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nitsche s method; antenna arrays; NASA almond; edge elements; scattering; explicit-implicit time-stepping; Maxwell s equations; Finite Element Method; mass lumping; stability analysis; Finite-Differences Time-Domain; periodic structures; shape and material optimization;

    Sammanfattning : In this thesis, a new hybrid method that combines the Finite Element Method (FEM) with the Finite-Difference in Time-Domain (FDTD) method is presented. Tetrahedrons in the unstructured FEM region are connected directly to thehexahedrons in the structured FDTD region. LÄS MER

  5. 4. Class of Accurate Low Order Finite Elements

    Författare :Magnus Fredriksson; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quadrilateral ; variational ; finite element ; element technology ; HuWashizu ; hexahedral ; Technological sciences; Teknik;

    Sammanfattning : High accuracy and low computational costs are essential properties for efficient finite element codes. Improvements of the finite element method in order to satisfy these qualities have been the subject for extensive research activities ever since its introduction. LÄS MER

  7. 5. Algebraic Dynamical Systems, Analytical Results and Numerical Simulations

    Författare :Robert Nyqvist; Andrei Khrennikov; Vladimir Anashin; Växjö universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; discrete dynamical systems; p-adic numbers; finite fields; number of periodic points; Chebotarev s Density Theorem; computational number theory; MATHEMATICS; MATEMATIK;

    Sammanfattning : In this thesis we study discrete dynamical system, given by a polynomial, over both finite extension of the fields of p-adic numbers and over finite fields. Especially in the p-adic case, we study fixed points of dynamical systems, and which elements that are attracted to them. We show with different examples how complex these dynamics are. LÄS MER