Sökning: "railway mechanics"

Visar resultat 6 - 10 av 67 avhandlingar innehållade orden railway mechanics.

  1. 6. Thermal impact on rolling contact fatigue of railway wheels

    Författare :Sara Caprioli; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railway wheels; Thermomechanical finite element analysis; Frictional rolling contact; Thermal fracture; Tread braking; Rolling contact fatigue;

    Sammanfattning : Rolling contact fatigue (RCF) is a very common and costly damage mechanism for rails and wheels. This thesis investigates the influence of combined thermal and mechanical loading on RCF of railway wheels on the basis of numerical predictions. LÄS MER

  3. 7. 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

  4. 8. Multi-objective optimization of railway bogie suspension damping

    Författare :Albin Johnsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railway vehicle dynamics; Bogie suspension design; Multi-objective optimization; Pareto optimized bogie primary and secondary suspensions damping;

    Sammanfattning : In this thesis multi-objective optimization is used to find Pareto fronts showing the set of optimized damping parameters of primary and secondary bogie suspensions. Special interests are put on requirements to enhance safety and comfort of a railway vehicle. LÄS MER

  5. 9. Long-term rail damage evolution in railway crossings

    Författare :Rostyslav Skrypnyk; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wear; S C; plasticity; wheel-rail contact mechanics; switches crossings; FEM; metamodel; Dynamic vehicle-track interaction;

    Sammanfattning : To accommodate the passage of wheels in intersecting traffic routes, fixed railway crossings have discontinuous rails leading to an intense load environment due to repeated wheel-rail impacts. This gives rise to high costs associated with repair and maintenance of the rails in the crossing. LÄS MER

  7. 10. Towards simulation-based optimisation of materials in railway crossings

    Författare :Rostyslav Skrypnyk; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wheel-rail contact mechanics; plasticity; metamodel; wear; S C; Dynamics vehicle-track interaction; switches crossings; FEM;

    Sammanfattning : Railway crossings are subjected to an intense load environment caused by the rail discontinuities needed to accommodate the passage of wheel flanges in intersecting traffic directions. This gives rise to high costs associated with repair and maintenance. LÄS MER