Sökning: "Moisture Gradients"

Visar resultat 1 - 5 av 31 avhandlingar innehållade orden Moisture Gradients.

1. 1. Static and Dynamic Modelling of the Drying Section of a Paper Machine

   Författare :Magnus Karlsson; Avdelningen för kemiteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pappers- och massateknik; Modelling; Wood; Paper; Multi-Cylinder; Simulation; Control; Steam; Air; Dew Point; Moisture Gradients; pulp and paper technology; Pressure Gradients;

   Sammanfattning : The paper making process involves chopping of wood, cooking and forming, followed by dewatering in a vacuum section, press section and drying section. Several models for the most important parts of the paper machine drying section are presented in this thesis to describe phenomena at steady state and during state transitions. LÄS MER

3. 2. Steel-to-timber dowel joints : Influence of moisture induced stresses

   Författare :Johan Sjödin; Hans Petersson; Carl-Johan Johansson; Per-Johan Gustavsson; Växjö universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; constraint stresses; contact-free measurement; dowel-type joints; humidity variations; moisture-induced deformations; timber structures; Building engineering; Byggnadsteknik; Byggteknik; Civil engineering;

   Sammanfattning : Joints are critical parts of timber structures, transmitting static and dynamic forces between structural members. The ultimate behavior of a loaded building depends strongly on the structural configuration and the capacity of the joints. LÄS MER

4. 3. Moisture-induced stress and distortion of wood : A numerical and experimental study of wood's drying and long-term behaviour

   Författare :Sara Florisson; Sigurdur Ormarsson; Johan Vessby; Kent Persson; Linnéuniversitetet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; analytical method; calibration; controlled climate; creep; distortion; experimental methodology; FEM; fibre orientation; mechano-sorption; moisture transport; natural climate; Norway spruce; numerical model; three-dimensional; timber beam; validation; wood; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

   Sammanfattning : With the current advances made in three-dimensional modelling of wood, it is possible to provide an overall picture of moisture flow, and moisture-induced stress and deformations, whereas previously, experiments only provided local measurements. The main aim of the doctoral thesis is to investigate the possibilities of the developed three-dimensional numerical model to predict the behaviour of wood when simultaneously exposed to a mechanical load and a particular climate. LÄS MER

5. 4. Moisture Induced Stresses in Timber Structures

   Författare :Johan Jönsson; Avdelningen för Konstruktionsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknik; load carrying capacity; Technological sciences; reinforcement; short-term strength perpendicular to grain; internal stresses; glulam; contact free measuring technique moisture gradients;

   Sammanfattning : Wood is a hygroscopic material; always striving to reach equilibrium with the surrounding air, and consequently the moisture content is different in different climate conditions. The strength of wood is directly dependent on the moisture content, lower moisture content leads to increasing strength. LÄS MER

7. 5. Moisture Induced Stress Perpendicular to Grain in Timber Structures

   Författare :Martin Häglund; Avdelningen för Konstruktionsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wood.; timber; perpendicular to grain; load combination factor; tensile stress; mechano-sorption; Moisture induced eigen-stress; varying moisture content;

   Sammanfattning : Timber structures and wooden element are in general affected by moisture and moisture variation in different ways. Their hygroscopic properties result in adsorption of water when wetted and in desorption when dried. LÄS MER