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Visar resultat 1 - 5 av 168 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Quasi-instantaneous and Long-term Deformations of High-Performance Concrete with Some Related Properties

   Författare :Bertil Persson; Avdelningen för Byggnadsmaterial; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shrinkage; Relative humidity; Long-term; Hydration; High-Performance Concrete; Elastic modulus; Deformations; Creep; Concrete; Cement; Quasi-instantaneous; Strength; Building construction; Byggnadsteknik;

   Sammanfattning : This report outlines an experimental and numerical study on quasi-instantaneous and long-term deformations of High-Performance Concrete, HPC, with some related properties. For this purpose about two hundred small cylinders and about one thousand cubes of eight types of HPC were cast. The age at loading varied between 18h and 28 days. LÄS MER

3. 2. Cracking in Reinforced Concrete Structures Due to Imposed Deformations

   Författare :Agnes Nagy; Avdelningen för Konstruktionsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; minimum reinforcement; cracking; softening; shrinkage; cooling; imposed deformations; conversion formula; static E-modulus; damping coefficient; resonance frequency; dynamic E-modulus; constitutive model; thermal stress; hydration process; reinforced concrete structure; early age; crack control; Building construction; Byggnadsteknik;

   Sammanfattning : This thesis is concerned with modeling of the cracking process in reinforced concrete due to imposed deformations. Cracking is investigated both at early ages, during hydration, and at mature age when the final properties of the concrete are reached. LÄS MER

4. 3. Simulation of additive manufacturing using a mechanism based plasticity model

   Författare :Andreas Malmelöv; Andreas Lundbäck; Mathias Wallin; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Residual stress; Material model; Alloy 625; Alloy 718; deformations; Finite Element Method; synchrotron X-ray diffraction; Solid Mechanics; Hållfasthetslära;

   Sammanfattning : This thesis presents finite element (FE) simulations of additive manufacturing (AM) and physically based material modeling of alloy 625 and alloy 718. In recent years, there has been an increasing interest in AM and there has been a dramatic increase in publications in the field. LÄS MER

5. 4. Multiscale modeling of dynamic recrystallization

   Författare :Ylva Mellbin; Hållfasthetslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic recrystallization; Crystal plasticity; Texture; Grain size strengthening; Vertex model; Nucleation; Particle pinning; Large deformations; Multiscale modeling; GPGPU;

   Sammanfattning : During thermomechanical processing of metals, changes occur in the microstructure of the material which affect its macroscopic properties. By understanding these transformations in the microstructure, it becomes possible to design the processes in a way which yields the desired properties in the finished product. LÄS MER

7. 5. Models and numerical procedures for fractional order viscoelasticity

   Författare :Klas Adolfsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sparse quadrature; a posteriori error estimate; a priori error estimate; viscoelasticity; adaptivity; fractional calculus; large deformations; integro-differential equation; internal variables;

   Sammanfattning : .... LÄS MER