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Visar resultat 11 - 15 av 334 avhandlingar som matchar ovanstående sökkriterier.

1. 11. Beam-to-Beam Contact and Its Application to Micromechanical Simulation of Fiber Networks

   Författare :Hamid Reza Motamedian; Artem Kulachenko; Umberto Perego; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber network; beam-to-beam contact; rotational contact; non-consistent; simulation; finite element; multiscale; microscale; micromechanics; paper; refining; beating; fine; hygroexpansion; shrinkage; drying; Hållfasthetslära; Solid Mechanics;

   Sammanfattning : This doctoral thesis covers the topic of modeling the three-dimensional fiber net- works with the finite element method. It contains the part addressing the numerical aspects of the modeling, namely, the contact formulation and application of the developed methods to the fundamental questions such as the effect of randomness in fiber properties and effect of fines and hygroexpansion. LÄS MER

3. 12. Towards the Identification of Wheel-Rail Contact Forces

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

   Sammanfattning : The accurate determination of the contact forces between rail and wheel is essential inthe analysis of different kinds of rolling contact fatigue. As the contact forces cannot bemeasured directly in the field, one approach is to measure the strain at certain positionsof an instrumented wheel. LÄS MER

4. 13. Simulation of contact, friction and wear in gears : a finite element approach

   Författare :Olle Lundvall; Linköpings universitet; []
   Nyckelord :Gears; Gear noise; Contact mechanics; Simulation; Friction; Wear; Transmission error;

   Sammanfattning : In this thesis, resent methods in computational contact mechanics is brought into the process of gear design. The finite element method is used to model two elastic bodies in contact. By defining a contact interface between these two bodies, constitutive laws, regarding normal contact, friction and wear, are included. LÄS MER

5. 14. 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

7. 15. Solution to boundary-contact problems of elasticity in mathematical models of the printing-plate contact system for flexographic printing

   Författare :Nikolai Kotik; Yury Shestopalov; Stig Larsson; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; boundary-contact problem; elasticity; integral equation; approximate decomposition; Applied mathematics; Tillämpad matematik; Matematik; Mathematics;

   Sammanfattning : Boundary-contact problems (BCPs) are studied within the frames ofclassical mathematical theory of elasticity and plasticityelaborated by Landau, Kupradze, Timoshenko, Goodier, Fichera andmany others on the basis of analysis of two- and three-dimensionalboundary value problems for linear partial differential equations.A great attention is traditionally paid both to theoreticalinvestigations using variational methods and boundary singularintegral equations (Muskhelishvili) and construction of solutionsin the form that admit efficient numerical evaluation (Kupradze). LÄS MER