Sökning: "sliding contact"

Visar resultat 16 - 20 av 152 avhandlingar innehållade orden sliding contact.

1. 16. Investigation of Forces and Contact Area for Modelling Turning Processes

   Författare :Ove Bayard; KTH; []
   Nyckelord :Modelling; turning processes; cutting forces; contact length; Quick Stop Device; QSD; simulation programs; FEM; predictive models.; NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : This thesis is focused on an investigation of forces andcontact area for modelling turning processes. The primary taskin short term research has been to take a first steptowards animproved model of the cutting process. LÄS MER

3. 17. Workpiece steels protecting cutting tools from wear : A study of the effects of alloying elements on material transfer and coating damage mechanisms

   Författare :Toshiharu Aiso; Staffan Jacobson; Urban Wiklund; Staffan Söderberg; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Metal cutting; Steel; Cutting tools; Transfer; Coating; Sliding; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Sammanfattning : The vision of this thesis is to improve the machinability of workpiece steels. Workpiece material frequently transfers to the cutting tools during machining, and the transfer layers then forming on the tools may give both good and bad effects on machining performance and tool life. LÄS MER

4. 18. Railway Wheel Flats. Martensite Formation, Residual Stresses, and Crack Propagation

   Författare :Johan Jergeus; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sliding contact; metallographic investigation; crack propagation; thermal shock; constitutive modelling; phase transformations; railway wheel flats; full-scale field experiments; transformation plasticity; tread damage; residual stresses; spalling; martensite formation;

   Sammanfattning : A railway wheel flat is a flat spot on the rolling surface of a wheel caused by its unintentional sliding on the rail. The reason for the sliding may be poorly adjusted, frozen or defect brakes, or too high braking forces in relation to the available wheel/rail adhesion. LÄS MER

5. 19. Thermal and mechanical behaviour of railway wheel steel

   Författare :Johan Ahlström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phase transformations; plastic deformation; sliding contact; heat conduction modelling; low cycle fatigue; railway wheel steel Fe-0.5C-0.3Si-0.75Mn-0.05V ; austenitisation; transformation kinetics; heat treatment; friction;

   Sammanfattning : The wish to increase loads and speeds of trains puts higher demand on construc¬tion, engineering and material than ever before. Therefore it is necessary to con¬tinuously develop technology to meet these increasing requirements. LÄS MER

7. 20. The Positive Effect of Nitrogen Alloying of Tool Steels Used in Sheet Metal Forming

   Författare :Irma Heikkilä; Staffan Jacobson; Sture Hogmark; Pavel Krakhmalev; Uppsala universitet; []
   Nyckelord :galling; nitrogen; tool steel; sliding contact; metal forming; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Sammanfattning : Sheet metal forming processes are mechanical processes, designed to make products from metal sheet without material removal. These processes are applied extensively by the manufacturing industry to produce commodities such as heat exchangers or panels for automotive applications. They are suitable for production in large volumes. LÄS MER