Sökning: "creep behaviour"

Visar resultat 6 - 10 av 83 avhandlingar innehållade orden creep behaviour.

1. 6. Volumetric Analysis in Mechanical Behaviour and Physical Ageing of Polymers

   Författare :Mats Delin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ageing rate; Gr neisen parameter; bulk modulus; KAHR model; dilatometry; Poisson s ratio; timescale; physical ageing; dynamic mechanical properties; stress relaxation; volume changes; creep; Doolittle s equation;

   Sammanfattning : Volumetric changes associated with the deformation of ideal elastic solids depends on elastic constants of the solid and applied strain. Their magnitude is easily determined from the corresponding Poisson's ratios. LÄS MER

3. 7. Creep aspects of softwood from the cell-wall level to structures

   Författare :Rhodel Bengtsson; E. Kristofer Gamstedt; Mahmoud Mousavi; Reza Afshar; Falk Wittel; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Creep; Solid Mechanics; Wooden Materials; Linear Viscoelasticity; Experiments; Materialvetenskap; Materials Science;

   Sammanfattning : This thesis addresses the intricate mechanical behaviour of natural materials, with a particular focus on wood. Despite millennia of use, understanding the mechanical behaviour of wood materials remains challenging due to their complex microstructures. LÄS MER

4. 8. 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. 9. Influence of Segregants on Creep Fracture in Powder Metallurgical Martensitic Stainless Steel

   Författare :Mats Norell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AES; creep; segregants; powder metallurgy; prior particle boundaries; atomisation; SIMS; martensitic stainless steel; ESCA; cavities; powder surfaces;

   Sammanfattning : This thesis deals with the behaviour of segregants in Powder Metallurgical (PM) 10%Cr steel and their impact on creep fracture. Particular interest is taken in determining the reaction products involved in creep cavitation and how these are connected to the powder surface reactions during the gas atomisation and consolidation (hot isostatic pressing). LÄS MER

7. 10. Mechano-sorptive Creep in Wood - Experimental Studies of the Influence of Material Properties

   Författare :Charlotte Bengtsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; material properties; deformation; shrinkage swelling; mechano-sorption; dynamic modulus of elasticity; creep;

   Sammanfattning : Mechano-sorptive creep deformations appear when wood is loaded under varying moisture conditions. These creep deformations are known to be larger than the creep deformations under constant humidity conditions. The present thesis deals with mechano-sorptive creep in Norway spruce wood. LÄS MER