Sökning: "contact mechanics chalmers"

Visar resultat 6 - 10 av 69 avhandlingar innehållade orden contact mechanics chalmers.

  1. 6. Inverse Identification of Dynamic Wheel-rail Contact Forces

    Författare :Hamed Ronasi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse problems; sensitivity; optimization; regularization; railway mechanics; input estimation; load identification;

    Sammanfattning : Accurate evaluation of contact forces between wheel and rail is essential in the assessmentof vehicle performance and to predict consequences of dynamic vehicle-track interaction.As the contact forces can not be measured directly in the field, one common approachis to measure the strain or acceleration at various positions on a wheel or wheel axle. LÄS MER

  3. 7. Crack growth paths in rolling contact fatigue — Numerical predictions

    Författare :Mohammad Salahi Nezhad; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vector crack tip displacement; Crack face friction; Crack growth direction; Crack propagation; Rolling contact fatigue;

    Sammanfattning : Rolling contact fatigue (RCF) cracks in railway wheels and rails are costly and complex to deal with. Despite the extensive research efforts that have been put into understanding the mechanisms and developing appropriate predictive models for RCF crack growth, there are still a lot of open questions. LÄS MER

  4. 8. Finite element procedures for crack path prediction in multi-axial fatigue

    Författare :Dimosthenis Floros; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fracture mechanics; Configurational forces; Mixed-mode; Numerical simulation; Rolling contact fatigue; Plasticity;

    Sammanfattning : Rolling Contact Fatigue (RCF) cracks in rails are among the most detrimental railway track defects regarding reliability and cost. The cracks typically grow in shear mode up to a certain length at which they might arrest or kink into a more tensile-driven growth. LÄS MER

  5. 9. Anisotropy in pearlitic steel subjected to rolling contact fatigue - modelling and experiments

    Författare :NASIM LARIJANI; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pearlitic steel; crack propagation; Rolling Contact Fatigue; Anisotropy; plasticity; High Pressure Torsion;

    Sammanfattning : In rails and wheels subjected to severe rolling/sliding contact, large plastic deformations accumulate in the surface layer. This decreases the fatigue resistance of components and makes this layer prone to formation of common rolling contact related defects. LÄS MER

  7. 10. A Novel Fiber Interaction Method for Simulation of Early Paper Forming

    Författare :Gustav Kettil; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber suspension flow model; object-object interaction model; contact forces; lay down simulations; paper forming; immersed boundary methods; contact forces;

    Sammanfattning : In the forming section of a paper machine, a fiber suspension is flowing down onto a forming fabric, and a paper structure is formed. By using computer simulations this process can be studied, attaining new knowledge helping to improve paper quality and machine efficiency. LÄS MER