Search for dissertations about: "contact theory"

Showing result 1 - 5 of 221 swedish dissertations containing the words contact theory.

2. 1. Time-domain modelling of curve squeal: a fast model for one- and two-point wheel/rail contact

   Author : Ivan Zenzerovic; Chalmers University of Technology; []
   Keywords : two-point contact; non-Hertzian contact; dynamics coupling; rolling contact; tangential point-contact model; Curve squeal; time domain; frictional instability;

   Abstract : Curve squeal is a type of railway noise that may arise when a railway vehicle negotiates a relatively tight curve. A single frequency, corresponding to a wheel mode, dominates the radiated sound, which makes squeal a very tonal noise. READ MORE

4. 2. Twisting and Gluing : On Topological Field Theories, Sigma Models and Vertex Algebras

   Author : Johan Källén; Maxim Zabzine; Mathias Blau; Uppsala universitet; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Topological field theory; Chern-Simons theory; Contact geometry; Sigma models; Poisson vertex algebras; Vertex algebras; String theory; Theoretical Physics; Teoretisk fysik;

   Abstract : This thesis consists of two parts, which can be read separately. In the first part we study aspects of topological field theories. We show how to topologically twist three-dimensional N=2 supersymmetric Chern-Simons theory using a contact structure on the underlying manifold. READ MORE

5. 3. On Efficient Modelling of Wheel-Rail Contact in Vehicle Dynamics Simulation

   Author : Matin Shahzamanian Sichani; Mats Berg; Roger Enblom; Asier Alonso; KTH; []
   Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wheel-rail contact; non-elliptic contact; rail vehicle dynamics; rolling contact; vehicle-track interaction; wheel-rail damage; Järnvägsgruppen - Fordonsteknik; Järnvägsgruppen - Fordonsteknik; Järnvägsgruppen - Tribologi; The KTH Railway Group - Tribology; Vehicle and Maritime Engineering; Farkostteknik;

   Abstract : The wheel-rail contact is at the core of all research related to vehicletrackinteraction. This tiny interface governs the dynamic performanceof rail vehicles through the forces it transmits and, like any high stressconcentration zone, it is subjected to serious damage phenomena. READ MORE

6. 4. Enforcing Legitimacy : Perspectives on the Relationship between Intervening Armed Forces and the Local Population in Afghanistan

   Author : Lisa Karlborg; Jan Ångström; Louise Olsson; Chiara Ruffa; Mimmi Söderberg Kovacs; Robert Egnell; Uppsala universitet; []
   Keywords : armed intervention; local legitimacy; Afghanistan; intervening armed forces; military; local population; perceptions; soldiers; ISAF; noncombat contact; peace operations; peacekeeping; military doctrine; contact theory; fieldwork; Peace and Conflict Research; Freds- och konfliktforskning;

   Abstract : Bolstering local perceptions of legitimacy in armed intervention has emerged as an important feature of increasingly complex international peace and statebuilding efforts. Yet, previous research has only begun to explore what local legitimacy entails to those involved in, and affected by, armed intervention. READ MORE

7. 5. Numerical simulation of thermomechanically coupled transient rolling contact - An arbitrary Lagrangian-Eulerian approach

   Author : Andreas Draganis; Chalmers University of Technology; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermomechanical coupling; finite element method; transient analysis; arbitrary Lagrangian--Eulerian; rolling contact; frictional contact;

   Abstract : Numerical simulation of rolling contact serves as an important complement to laboratory and full-scale testing in the endeavour to further the understanding of related physical mechanisms, e.g. the influence of friction on the rolling motion, the thermomechanical interaction, damage phenomena and related modes of failure. READ MORE