Sökning: "linear viscoelasticity"

Visar resultat 1 - 5 av 26 avhandlingar innehållade orden linear viscoelasticity.

  1. 1. Fractional Calculus and Linear Viscoelasticity in Structural Dynamics

    Författare :Mikael Enelund; [1996]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; linear viscoelasticity; convolution integrals; anisotropy; structural modeling; finite elements; material damping; time integration; internal variables; relaxation; fractional calculus; creep; Mittag-Leffler functions;

    Sammanfattning : The use of linear viscoelasticity together with fractional calculus in time-domain structural modeling is studied. Both constitutive and structural aspects are investigated. LÄS MER

  2. 2. The Finite Element Method for Fractional Order Viscoelasticity and the Stochastic Wave Equation

    Detta är en avhandling från Göteborg : Chalmers University of Technology and University of Gothenburg

    Författare :Fardin Saedpanah; Göteborgs universitet.; Gothenburg University.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element method; continuous Galerkin method; linear viscoelasticity; fractional calculus; fractional order viscoelasticity; weakly singular kernel; stability; a priori error estimate; a posteriori error estimate; stochastic wave equation; additive noise; Wiener process; strong convergence.; linear viscoelasticity; continuous Galerkin method; fractional order viscoelasticity; Wiener process; fractional calculus; a posteriori error estimate; weakly singular kernel; a priori error estimate; stability; stochastic wave equation; additive noise; strong convergence.;

    Sammanfattning : This thesis can be considered as two parts. In the first part a hyperbolic type integro-differential equation with weakly singular kernel is considered, which is a model for dynamic fractional order viscoelasticity. In the second part, the finite element approximation of the linear stochastic wave equation is studied. LÄS MER

  3. 3. Thermally Induced Fracture Performance of Asphalt Mixtures

    Detta är en avhandling från Göteborg : Chalmers University of Technology and University of Gothenburg

    Författare :Prabir Kumar Das; Björn Birgisson; Dallas Little; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low temperature cracking; asphalt concrete fracture mechanics; viscoelasticity; non-linear thermal contraction coefficient; atomic force microscopy; wax; wax crystallization; SRA - Transport; SRA - Transport;

    Sammanfattning : A major distress mode in asphalt pavements is low temperature cracking, which results from the contraction and expansion of the asphalt pavement under extreme temperature changes. The potential for low temperature cracking is an interplay between the environment, the road structure and importantly the properties of the asphalt mixture. LÄS MER

  4. 4. Respiratory mechanics during mechanical ventilation in health and in disease

    Detta är en avhandling från Department of Clinical Physiology, Lund University

    Författare :Cecilia Svantesson; [1997]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Recruitment; Collapse; Overdistension; Viscoelasticity; Elastic pressure-volume curve; Respiratory disease; Health; Human; Rabbit; Positive end-expiratory pressure; Anaesthesiology; intensive care; Anestesiologi; intensivvård;

    Sammanfattning : The elastic pressure-volume (Pel-V) curve of the respiratory system can be used as a guide for improved ventilator management. It may indicate risks of lung damage associated with collapse or overdistension of lung units. LÄS MER

  5. 5. Robust Preconditioners Based on the Finite Element Framework

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Erik Bängtsson; Maya Neytcheva; Per Lötstedt; Svetozar Margenov; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; FEM; iterative solution method; algebraic multilevel preconditioner; sparse approximate inverse; block preconditioner; Schur complement approximation; nonsymmetric saddle point matrix; isostatic glacial adjustment; pre-stress advection; elasticity; viscoelasticity; in compressible solid; ABAQUS; BEM DDM; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Robust preconditioners on block-triangular and block-factorized form for three types of linear systems of two-by-two block form are studied in this thesis.The first type of linear systems, which are dense, arise from a boundary element type of discretization of crack propagation problems. LÄS MER