Sökning: "Contact mechanics"

Visar resultat 36 - 40 av 249 avhandlingar innehållade orden Contact mechanics.

  1. 36. Almost-axial impact on elastic and viscoelastic cantilever columns

    Författare :Lixing Ren; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Almost-axial impact between a rigid body and a cantilever column is studied. A preliminary study of the contact process is presented for a flat-ended impacting body and a flat-ended elastic Timoshenko column with rectangular cross-section. The equations of motion pertaining to the column are solved using an explicit finite difference method. LÄS MER

  3. 37. Investigation and simulation of tool wear in press hardening

    Författare :Liang Deng; Göran Berglund; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Due to the requirements of higher strength components and lower carbon dioxide emission, press hardening becomes prevalent in the automotive industry. Heating a boron alloyed steel blank to obtain the austensite phase at high temperature and quenching it to martensitic phase enhances the strength of the products and still allows complex shapes. LÄS MER

  4. 38. Mechanical impedance gauge based on measurement of strains on a vibrated or impacted rod

    Författare :Lars Lagerkvist; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : A mechanical impedance gauge based on measurement of strains at two cross-sections of a slender rod is studied. The gauge rod is in contact with the object at one end while the other end is excited harmonically with a vibrator or transiently through the impact of a hammer. LÄS MER

  5. 39. 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. 40. Modelling of wear and galling in press hardening simulations

    Författare :Liang Deng; Mats Oldenburg; Karl Nielsen; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Implementation of press hardened parts in automobile responses to the requirement of reduced carbon dioxide emission because the press hardened part has very high ratio of strength to weight. Furthermore, ultra high-strength steels (press hardened parts) increases the vehicle safety. LÄS MER