Sökning: "Moisture strain stress"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden Moisture strain stress.

  1. 1. 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

  3. 2. Baggy paper webs : Effect of uneven moisture and grammage profiles in different process steps

    Författare :Cecilia Land; Lennart Stolpe; Kaarlo Niskanen; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bagginess; drying; calendering; grammage; moisture content; paper; profile; reels; softwood kraft pulp; storage; strain; tension; web; Chemical Engineering; Kemiteknik;

    Sammanfattning : One of the problems encountered in paper converting is caused by the occurrence of "baggy webs", which essentially is when the tension profile of the paper web is uneven. In an area with low tension the paper is longer, which results in bagginess. LÄS MER

  4. 3. Clothing Evaporative Resistance: Its Measurements and Application in Prediction of Heat Strain

    Författare :Faming Wang; Ergonomi och aerosolteknologi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal manikin; clothing ensemble; evaporative resistance; localised evaporative resistance; thermophysiological response; heat stress; heat strain; the Predicted Heat Strain PHS model;

    Sammanfattning : Clothing evaporative resistance is one of the most important inputs for both the modelling and for standards dealing with thermal comfort and heat stress. It might be determined on guarded hotplates, on sweating manikins or even on human subjects. LÄS MER

  5. 4. Experimental characterization and numerical modeling of compression perpendicular to the grain in wood and cross-laminated timber

    Författare :Shaheda T. Akter; Thomas K. Bader; Erik Serrano; Jan Oscarsson; Reinhard Brandner; Linnéuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rolling shear; biaxial testing; stress combination; RT-plane; moisture influence; rolling shear creep; digital image correlation; strain field; CLT connection; rotational stiffness; rullskjuvning; biaxiell undersökning; spänningskombination; RT-plan; fuktpåverkan; krypning vid rullskjuving; digital bildkorrelation; töjningsfält; KLTanslutning; rotationsstyvhet; Byggteknik; Civil engineering;

    Sammanfattning : Compression perpendicular to the grain (CPG) of wood is a typical loading situation in timber structures. It has been an extensively studied research topic for decades, due to the highly ductile behavior of wood under such loading, the large variations in mechanical properties, and the relevance of these properties in structural design. LÄS MER

  7. 5. Constitutive Modelling and Finite Element Analysis of Concrete Structures with Regard to Environmental Influence

    Författare :Ola Dahlblom; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Finite Elemente Method; Constitutive model; Concrete; Environment; Moisture; Drying; Temperature; Fracture; Fictitious crack model; Smeared Crack; Creep; Shrinkage; Pickett Effect;

    Sammanfattning : A constitutive model for concrete is formulated. Tensile fracture is described using a smeared crack approach where the fracrure energy is considered and the shear stiffneess in the cracked region is gradually reduced as crackling develops. LÄS MER