Sökning: "stick-slip"

Visar resultat 1 - 5 av 26 avhandlingar innehållade ordet stick-slip.

1. 1. Force measurements using scanning probe microscopy : Applications to advanced powder processing

   Författare :Anders Meurk; KTH; []
   Nyckelord :atomic force microscope; AFM; SPM; van der Waals interaction; DLVO-theory; surface forces; colloidal probe; force curve; friction; adhesion; stick-slip; cantilever; calibration; spring constant; silicon nitride; iron; silica;

   Sammanfattning : The object of this thesis is to apply scanning probemicroscopy (SPM) to the field of advanced powder processing.Measurement of interparticle surface forces at conditionsrelevant to ceramic processing has been performed together withthorough studies of powder friction. LÄS MER

3. 2. Dynamic Wetting of Solid Surfaces, Influence of Surface Structures and Surface Active Polymers

   Författare :Stina Gerdes; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; stick-slip; Wilhelmy plate; block copolymers; surface active polymers; surface channels; spreading; contact angles; dynamic wetting; surface structures; Fysikalisk kemi;

   Sammanfattning : The effect of surface structures on the dynamics of wetting was investigated through measurements of the dynamic contact angle and spreading velocity of oil droplets spreading over surfaces with parallel and gridlike V-shaped channels. A rim of liquid was observed to spread out in the channels ahead of the dropfront after a short time of spreading (seconds). LÄS MER

4. 3. Dynamiskt belastade tribologiska system under plastisk formning, del II --- analyserade genom akustisk emission

   Författare :Thomas Skåre; Industriell Produktion; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; supervision; wear; waves; vibrations; tribology; surfaces; stick-slip; sliding; sheet metal; quality check; plastic forming; monitoring; galling; machining; deep drawing; friction; cracking; contact surfaces; Acoustic emission AE ; contact pressure; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Material technology; Materiallära; materialteknik; Production technology; Produktionsteknik;

   Sammanfattning : The dynamic friction process and contact surface between tool and working material in a plastic forming process is hard to describe in mathematical form and hard to monitor and control in real time. High production speed and highly optimised forming operations result in great demands on the control equipment. LÄS MER

5. 4. Fracture behaviour of Green Wood (Pinus Sylvestris L.) : a composite materials approach

   Författare :Fredrik Thuvander; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymera konstruktionsmaterial; Polymeric Composite Materials;

   Sammanfattning : The fracture behaviour of green wood has been investigated using a composite materials approach. Through fracture experiments on miniature specimens, it was found that drying of wood leads to damage not only on the macro-level but also at the scale of the cell wall. LÄS MER

7. 5. Novel Technique to Improve High-Velocity Cold Compaction : Processing of Polymer Powders and Polymer-Based Nanocomposite High Performance Components

   Författare :Bruska Azhdar; Bengt Stenberg; Leif Kari; Mikael Rigdahl; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer powders; nanocomposites; high-velocity compaction; high-energy ball milling; Manufacturing engineering; Produktionsteknik;

   Sammanfattning : Compaction of polymer powders and polymer-based nanocomposites by uniaxial high-velocity cold compaction (HVC), by high-energy ball milling (HEBM) and using a novel technique, relaxation assists, was investigated with a focus on the process parameters, the compactibility characteristics, surface morphology and friction. The basic phenomena associated with HVC are explained and the general energy principle is introduced to explain the pull-out phenomenon, springback gradient, delay time, relative time of the pressure wave, and stick-slip phenomenon during the compaction process. LÄS MER