Sökning: "Reijo Kouhia"

Hittade 5 avhandlingar innehållade orden Reijo Kouhia.

  1. 1. Energy-momentum conserving time-stepping algorithms for nonlinear dynamics of planar and spatial Euler-Bernoulli/Timoshenko beams

    Författare :Sophy Chhang; Jean-Marc Battini; Mohammed Hjiaj; Reijo Kouhia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear Dynamics; Energy-momentum conserving scheme; 2D co-rotational beam; Geometrically exact 3D Euler-Bernoulli beam; impact; Byggvetenskap; Civil and Architectural Engineering;

    Sammanfattning : Large deformations of flexible beams can be described using either the co-rotational approach or the total Lagrangian formalism. The co-rotational method is an attractive approach to derive highly nonlinear beam elements because it combines accuracy with numerical efficiency. LÄS MER

  3. 2. Nonlinear dynamics of flexible structures using corotational beam elements

    Författare :Thanh-Nam Le; Jean-Marc Battini; Reijo Kouhia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; corotational method; nonlinear dynamics; large displacements; finite rotations; time stepping method; thin-walled cross-section; beam element;

    Sammanfattning : The purpose of this thesis is to develop corotational beam elements for the nonlinear dynamic analyse of flexible beam structures. Whereas corotational beam elements in statics are well documented, the derivation of a corotational dynamic formulation is still an issue. LÄS MER

  4. 3. Inflation Mechanics of Hyperelastic Membranes

    Författare :Amit Patil; Anders Eriksson; Arne Nordmark; Reijo Kouhia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Membrane Mechanics; Inflation; Adhesive Contact; Instabilities; Bifurcation; Limit Point; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : The applications of inflatable membrane structures are increasing rapidly in the various fields of engineering and science. The geometric, material, force and contact non-linearities complicate this subject further, which in turn increases the demand for computationally efficient methods and interpretations of counter-intuitive behaviors noted by the  scientific community. LÄS MER

  5. 4. Topology Optimization for Additive Manufacturing Involving High-Cycle Fatigue

    Författare :Shyam Suresh; Anders Klarbring; Stefan B Lindström; Carl-Johan Thore; Bo Torstenfelt; Reijo Kouhia; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Additive Manufacturing (AM) is gaining popularity in aerospace and automotive industries. This is a versatile manufacturing process, where highly complex structures are fabricated and together with topology optimization, a powerful design tool, it shares the property of providing a very large freedom in geometrical form. LÄS MER

  7. 5. Numerical instability investigations for thin membranes

    Författare :Yang Zhou; Anders Eriksson; Arne Nordmark; Reijo Kouhia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Membrane structures are commonly used in many fields. The studies of these structures are of increasing interest. The projects in this thesis focus on the evaluations of equilibrium states for pressurized membranes under different problem settings, using finite element methods, and the corresponding instability behaviors. LÄS MER