Sökning: "constitutive model"

Visar resultat 1 - 5 av 328 avhandlingar innehållade orden constitutive model.

  1. 1. Constitutive Modelling and Finite Element Analysis of Concrete Structures with Regard to Environmental Influence

    Författare :Ola Dahlblom; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Finite Elemente Method; Constitutive model; Concrete; Environment; Moisture; Drying; Temperature; Fracture; Fictitious crack model; Smeared Crack; Creep; Shrinkage; Pickett Effect;

    Sammanfattning : A constitutive model for concrete is formulated. Tensile fracture is described using a smeared crack approach where the fracrure energy is considered and the shear stiffneess in the cracked region is gradually reduced as crackling develops. LÄS MER

  3. 2. Fatigue life prediction of additively manufactured ductile nickel-based superalloys : Constitutive and crack initiation modelling

    Författare :Thomas Lindström; Daniel Leidermark; Kjell Simonsson; Robert Eriksson; Magnus Ekh; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Additive manufacturing; Low-cycle fatigue; Thermomechanical fatigue; Constitutive modelling; Anisotropy;

    Sammanfattning : This dissertation was produced at the Division of Solid Mechanics at Linköping University, and is the final result of a project that included mechanical testing and modelling of an additively manufactured ductile nickel-based superalloy.The main objective of the work presented in this thesis was to investigate and model the cyclic behaviour and the fatigue life behaviour of an additively manufactured ductile nickel-based superalloy, with emphasis on modelling the stabilised material behaviour, by which fatigue life predictions can be based upon. LÄS MER

  4. 3. Cemented Carbide Sintering : Constitutive Relations and Microstructural Evolution

    Författare :Anders Petersson; KTH; []
    Nyckelord :Cemented carbides; Sintering; Constitutive relations; Microstructure; Densification; Modelling;

    Sammanfattning : Cemented carbides based on tungsten carbide and cobalt arecommonly produced by a powder metallurgy route including liquidphase sintering. The pressed compact densifies to almost halfits volume during sintering due to pore elimination. LÄS MER

  5. 4. Micro-mechanical mechanisms for deformation in polymer-material structures

    Författare :Jessica Strömbro; Peter Gudmundson; Per Gradin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Length-scale effects; Strain gradient; Moisture change; Humidity change; Network model; Fibre model; Mathematical model; Polymer; Micro-indentation; Particle composite; Interfacial debonding; Matrix cracking; Paper; Mechano-sorptive creep; Accelerated creep; Other materials science; Övrig teknisk materialvetenskap;

    Sammanfattning : In this thesis, the focus has been on micro-mechanical mechanisms in polymer-based materials and structures. The first part of the thesis treats length-scale effects on polymer materials. Experiments have showed that the smaller the specimen, the stronger is the material. LÄS MER

  7. 5. On a biomechanical approach to analysis of stability and load bearing capacity of oral implants

    Författare :Anders Halldin; Malmö högskola; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; animal model; bone resorption; implant stability; cortical bone; viscoelastic-viscoplastic; creep remodeling; constitutive model;

    Sammanfattning : IntroductionWhen an implant is placed in the bone the body responds to thetrauma by encapsulating the implant and its survival depends onthe ability for hard tissue encapsulation. The stability of the implantduring the healing phase is essential to achieve a good result[1]. Biological, physiological and mechanical phenomena affectimplant stability. LÄS MER