Search for dissertations about: "adaptivity"

Showing result 1 - 5 of 73 swedish dissertations containing the word adaptivity.

  1. 1. Model Adaptivity in Elasticity

    Author : David Heintz; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite element method; dimension reduction; a posteriori error; model error; model adaptivity; model error;

    Abstract : We consider model adaptivity in elasticity for dimensionally reduced forms, and shall treat different conceptual approaches. The basic idea, however, is to adaptively refine, not only the computational mesh, but also the underlying mathematical formulation. READ MORE

  2. 2. Postprocessing Techniques and Adaptivity in the Finite Element Method

    Author : Fethi Abdulwahab; Chalmers University of Technology; []
    Keywords : error estimation; postprocessing; adaptivity; superconvergence; finite element;

    Abstract : The Finite Element (FE) method is an approximate method and as such the accuracy of its solutions must be controlled to allow for a reliable application. This thesis deals with error estimation and improvements of the FE solutions based on superconvergent properties of the FE solution in certain points. READ MORE

  3. 3. Eigenfrequency Analysis FE-Adaptivity and a Nonlinear Eigenproblem Algorithm

    Author : Patrik Hager; Chalmers University of Technology; []
    Keywords : nonlinear eigenvalue; finite element; adaptivity; superconvergent patch recovery; rational krylov;

    Abstract : Engineering often pose the problem of computing the frequencies with which a system oscillates and the corresponding displacement patterns the system forms, and in case damping is present then the rates of which the amplitudes of the displacement patterns decay are also required. It is necessary to compute these quantities within a prescribed accuracy and the effort required for the computations should be minimised. READ MORE

  4. 4. Automation of Computational Mathematical Modeling

    Author : Anders Logg; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Keywords : computational mathematical modeling; automation; adaptivity; multi-adaptivity; individual time steps; dual problem; a priori; a posteriori; model reduction; individual time steps;

    Abstract : This thesis concerns the Automation of Computational Mathematical Modeling (CMM), involving the key steps of automation of (i) discretization, (ii) discrete solution, (iii) error control, (iv) modeling, and (v) optimization. The automation of (i)--(ii) is realized through multi-adaptive Galerkin methods on general discretizations of space-time with time steps variable in space. READ MORE

  5. 5. Goal-Oriented Adaptive Finite Element Analysis in Computational Material Mechanics

    Author : Fredrik Larsson; Chalmers University of Technology; []
    Keywords : visco-plasticity; a posteriori error estimation; thermo-elasticity; mesh refinement; adaptivity; FEM; elasticity;

    Abstract : This thesis is concerned with error control in computational material mechanics. A posteriori error estimation and adaptivity for finite element discretizations is investigated. Based on the technique of solving a dual problem, it is possible to control the accuracy of arbitrary quantities. READ MORE