Sökning: "Coefficient of Friction"

Visar resultat 21 - 25 av 169 avhandlingar innehållade orden Coefficient of Friction.

1. 21. On Surface Topography of Steel Sheet for Car Bodies

   Författare :Magnus Jonasson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; paint appearance; forming; steel sheet; bearing area; 3D surface roughness; area parameters; ball filter; friction; surface topography;

   Sammanfattning : This thesis is a contribution to the scientific area of surface topography on sheet metal surfaces. The studies are restricted to exploring the influence of the steel sheet,s surface topography on forming properties and on appearance after painting. LÄS MER

3. 22. Roller skis' rolling resistance and grip characteristics : influences on physiological and performance measures in cross-country skiers

   Författare :Mats Ainegren; Peter Carlsson; Marko Laaksonen; Mittuniversitetet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Adjustable grip; blood lactate; centre of pressure; cycle length; cycle rate; economy; efficiency; friction coefficient; heart rate; normal force; OBLA; oxygen uptake; power; ratcheted wheel; ratings of perceived exertion; roller skis; rolling resistance; tangential force; time to exhaustion;

   Sammanfattning : The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers. LÄS MER

4. 23. On the influence of surface roughness on rolling contact forces

   Författare :Oskar Lundberg; Ines Lopez Arteaga; Leif Kari; Matthias Kröger; KTH; []
   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; Rolling contact; Surface roughness; Contact forces; Contact modelling; Friction; Road; Asphalt; Substrate; Test-rig; Sliding; Stick–slip; Tyre; Rubber; Tread-block; Wheel–rail interaction; Vehicle and Maritime Engineering; Farkostteknik;

   Sammanfattning : Road vehicle tyres, railway wheels and ball bearings all generate rolling contact forces which are transferred within a finite area of contact between the rolling element and the substrate. Either it is visible or not for the human eye, a certain degree of roughness is always present on the contacting surfaces and it influences the generation of both vertical and lateral contactforces. LÄS MER

5. 24. On efficient and adaptive modelling of friction damping in bladed disks

   Författare :Mohammad Afzal; Leif Kari; Ines Lopez Arteaga; Muzio M Gola; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High cycle fatigue; Friction contact; Jacobian matrix; Shroud contact; Strip damper; Multiharmonic balance method; Contact stiffness; Cyclic symmetry; Nodal diameter; Magnetostrictive actuator; Magnetic field; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : This work focuses on efficient modelling and adaptive control of friction damping in bladed disks. To efficiently simulate the friction contact, a full-3D time-discrete contact model is reformulated and an analytical expression for the Jacobian matrix is derived that reduces the computation time drastically with respect to the classical finite difference method. LÄS MER

7. 25. Additive-Driven Improvements in Interfacial Properties and Processing of TMP-Polymer Composites

   Författare :Seyedehsan Hosseini; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; molybdenum disulfide; magnesium stearate; thermomechanical pulp; alkyl ketene dimer; friction; rheology;

   Sammanfattning : Efforts to address environmental concerns have resulted in new regulations designed to plan the reduction of plastic and synthetic polymer usage, necessitating the search for sustainable natural alternatives with comparable cost-effectiveness and mechanical performance. Thermomechanical pulp (TMP) fibres are one of the most affordable natural fibres that have no chemical refining in production, production have a high yield of 90-98% and TMP fibres have been demonstrated to improve the mechanical characteristics (strength, stiffness and toughness) of wood-polymer composites (WPCs) compared to the pure polymer. LÄS MER