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Visar resultat 11 - 15 av 17 avhandlingar som matchar ovanstående sökkriterier.

1. 11. Hygroelastic behaviour of wood-fibre based materials on the composite, fibre and ultrastructural level

   Författare :Razvan Cristian Neagu; Kristofer Gamstedt; Staffan Toll; KTH; []
   Nyckelord :wood fibres; ultrastructure; structure-property relations; microfibril angle; composites; characterization methods; hygroelastic properties; micromechanics; modelling; reinforcement potential; TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : Wood fibres can be used as reinforcement in plastics for load carrying purposes. Some advantages compared with conventional man-made fibres are that wood fibres come from a renewable resource, have high specific stiffness and strength, are generally less hazardous to health, biodegradable, and can be manufactured at low cost and high volumes. LÄS MER

3. 12. Modeling the mechanical performance of natural fiber composites

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

   Sammanfattning : Due to environmental concerns the interest in use of renewable and recyclable materials has dramatically increased over the recent years. Wood and other lignocellulosic fiber reinforced polymers have large potential as structural materials due to the high specific stiffness, high specific strength and high aspect ratio of the fibers. LÄS MER

4. 13. Analysis of the time and humidity-dependent mechanical behaviour of paper webs at offset printing preess conditions

   Författare :Jan Lif; KTH; []
   Nyckelord :creep; deformation; dynamic test; ;

   Sammanfattning : This thesis deals with the time, frequency andhumidity-dependent mechanical behaviour of paper webs at offsetprinting press conditions. How the paper web, the set-up andrunning conditions alter press performance is not fullyunderstood, and are difficult to isolate and investigateexperimentally. LÄS MER

5. 14. Micro-mechanical mechanisms for deformation in polymer-material structures

   Författare :Jessica Strömbro; Peter Gudmundson; Per Gradin; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Length-scale effects; Strain gradient; Moisture change; Humidity change; Network model; Fibre model; Mathematical model; Polymer; Micro-indentation; Particle composite; Interfacial debonding; Matrix cracking; Paper; Mechano-sorptive creep; Accelerated creep; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : In this thesis, the focus has been on micro-mechanical mechanisms in polymer-based materials and structures. The first part of the thesis treats length-scale effects on polymer materials. Experiments have showed that the smaller the specimen, the stronger is the material. LÄS MER

7. 15. Micro-mechanically based modeling of mechano-sorptive creep in paper

   Författare :Johan Alfthan; Peter Gudmundson; Staffan Toll; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; applied mechanics; materials science; packaging; Materialvetenskap; Materials science; Teknisk materialvetenskap;

   Sammanfattning : The creep of paper is accelerated by moisture content changes. This acceleration is known as mechano-sorptive creep, which is also found in wood and some other materials. Mechano-sorptive creep has been known for several decades but it is still not well understood, and there is no generally accepted model explaining the effect. LÄS MER