Sökning: "Tangential Derivations"

Hittade 4 avhandlingar innehållade orden Tangential Derivations.

  1. 1. Tangential Derivations, Hilbert Series and Modules over Lie Algebroids

    Författare :Yohannes Tadesse; Rolf Källström; Michael Granger; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Tangential Derivations; Monomials; Multiplier Ideals; Lie Algebroids; Hilbert series; Mathematics; matematik;

    Sammanfattning : Let A/k be a local commutative algebra over a field k of characteristic 0, and T_{A/k} be the module of k-linear derivations on A. We study, in two papers, the set of k-linear derivations on A which are tangential to an ideal I of A (preserves I), defining an A-submodule T_{A/k}(I) of T_{A/k}, which moreover is a k-Lie subalgebra. LÄS MER

  2. 2. Robust Formulations for Beam-to-Beam Contact

    Författare :Hamid Reza Motamedian; Artem Kulachenko; Anders Klarbring; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structures; Finite Element Methods; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Contact between beam elements is a specific category of contact problems which was introduced by Wriggers and Zavarise in 1997 for normal contact and later extended by Zavarise and Wriggers to include tangential and frictional contact. In these works, beam elements are assumed to have rigid circular cross-sections and each pair of elements cannot have more than one contact point. LÄS MER

  3. 3. Beam-to-Beam Contact and Its Application to Micromechanical Simulation of Fiber Networks

    Författare :Hamid Reza Motamedian; Artem Kulachenko; Umberto Perego; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber network; beam-to-beam contact; rotational contact; non-consistent; simulation; finite element; multiscale; microscale; micromechanics; paper; refining; beating; fine; hygroexpansion; shrinkage; drying; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : This doctoral thesis covers the topic of modeling the three-dimensional fiber net- works with the finite element method. It contains the part addressing the numerical aspects of the modeling, namely, the contact formulation and application of the developed methods to the fundamental questions such as the effect of randomness in fiber properties and effect of fines and hygroexpansion. LÄS MER

  4. 4. Modelling of dynamic and quasistatic events with special focus on wood-drying distortions

    Författare :Mats Ekevad; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Träteknik; Wood Technology;

    Sammanfattning : This thesis deals mainly with computer simulations of wood-drying distortions, especially twist. The reason for this is that such distortions often appear in dried timber, and the results are quality downgrades and thus value losses in the wood value chain. LÄS MER