Sökning: "hierarchical heterogeneities"

Hittade 3 avhandlingar innehållade orden hierarchical heterogeneities.

  1. 1. Rapid sintering of ceramics by intense thermal radiation

    Författare :Duan Li; Zhijian Shen; Lutz-Michael Berger; Stockholms universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sintering; sintering by intense thermal radiation; spark plasma sintering; heat transfer; mass transfer; scattering; coalescence; densification; grain growth; numerical simulation; porous ceramic; foaming; nanostructure; hierarchical heterogeneities; permeability; Materials Chemistry; materialkemi;

    Sammanfattning : Sintering is an important processing step for obtaining the necessary mechanical stability and rigidity of ceramic bulk materials. Both mass and heat transfer are essential in the sintering process. The importance of radiation heat transfer is significantly enhanced at high temperatures according to the well-known Stefan-Boltzmann’s law. LÄS MER

  3. 2. Numerical methods and multi-scale modeling for phase-field fracture - With applications in linear elastic and poro-elastic media

    Författare :Ritukesh Bharali; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; fracture; multiphysics; finite element; multiscale; desiccation; solvers; fracking; phase-field; solution techniques;

    Sammanfattning : This thesis presents novel numerical methods and a multi-scale modelling framework tailored for advancing the phase-field fracture model with applications in linear elastic and poro-elastic media. In the realm of the numerical methods, the focus lies on devising computationally efficient and robust monolithic solution techniques. LÄS MER

  4. 3. Mechanical properties of sound and of deteriorated softwood at different length scales : Poromicromechanical modeling and experimental investigations

    Författare :Thomas K. Bader; Karin Hofstetter; Kristofer Gamstedt; Austria Vienna University of Technology; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : Due to its natural origin and its inherent heterogeneities, mechanical properties of wood are highly anisotropic and show a broad variability, not only between different wood species, but also within a tree. Similar to other biological materials, the wood mi- crostructure is well organized and hierarchically structured from the annual rings visible to the naked eye down to the wood polymers cellulose, hemicellulose, and lignin at the nanometer-scale. LÄS MER