Now showing items 41-50 of 91
‘Nach und nach müssen wir alles ablehnen’: Hyperbolische Negativität bei Thomas Bernhard
Thomas Bernhard's work abounds in rejections. The impulse of not wanting to participate, of refusing to be complicit, lies at the heart of Bernhard's oeuvre. If this refusal is frequently embedded in discursive or even programmatic strategies, it really seems to undermine its own foundations, the very arguments and justifications put forward to make the refusal possible. Before being directed at a specific object, the refusal appears to stem from a more general disposition to say no. Drawing on Der Keller (1976), the ...
Numerical simulation of flow processes of wood‐polymer in extrusion dies
The addition of wood to polymers results in wood‐polymer composites (WPC), whereby the wood content can be up to 80 %. This composite is mainly processed in extruded deckings. The extrusion die is an essential part of the process, which determines both process parameters and the final product. A characteristic of WPC extrusion dies is a partial solidification of the melt before leaving the die. This solidification is necessary to ensure a dimensionally stable extrusion. For the design of WPC extrusion dies numerical ...
On A Hybrid Concept for Approximating Self‐Excited Periodic Oscillations of Large‐Scaled Dynamical Systems
Concerning the approximation of self‐excited periodic oscillations in large‐scaled mechanical systems involving strong nonlinearities, this contribution suggests a concept for an efficient treatment. The presented Hybrid FD‐HB method takes the advantages of both schemes Harmonic Balance and Finite Difference to enhance the ratio of computational cost and accuracy for mechanical systems with many degrees of freedom. Within this contribution the residual equations, required when applying a NEWTON‐RAPHSON‐scheme, are ...
Numerical Simulation of Viscoelastic Fluid‐Structure Interaction Problems and Drug Therapy in the Eye
The vitreous is a fluid‐like viscoelastic transparent medium located in the center of the human eye and is surrounded by hyperelastic structures like the sclera, lens and iris. This naturally gives rise to a fluid‐structure interaction (FSI) problem. While the healthy vitreous is viscoelastic and described by a viscoelastic Burgers‐type equation, the aging vitreous liquefies and is therefore modeled by the Navier‐Stokes equations. We derive a monolithic variational formulation employing the arbitrary Lagrangian ...
Damping based on electromagnetic induction: A comparison of different minimal models
Damping of structural vibrations is a crucial part of modern engineering. Using electromagnetic interactions for this purpose is a modern and promising approach. To gain better understanding of phenomena involved in this technique investigations on minimal models of a B‐field modulation dampers are shown. Therefore two different setups are compared. One uses a permanent magnet as the source for the magnetic field, one uses a coil, respectively an electro‐magnet as the source. The contribution focuses on differences ...
Derivation of Analytical, Closed‐form Formulas for the Calculations of Instantaneous Screw Axes of Arbitrary Rigid 3D Multi‐Body Systems
A method to calculate the parameters for each instantaneous and relative instantaneous screw axis in an arbitrary rigid multi‐body system is presented. At first a kinematic analysis is performed which calculates the displacements of all nodes and the rotation of each body. In the next step the displacements of the nodes and the rotation of the bodies are used to calculate the instantaneous screw axis of each body. With the information on the instantaneous screw axes the instantaneous relative screw axes can be computed ...
Psychische Belastungen bei Müllwerkern – Konsequenzen für die Beratungstätigkeit
Um die psychischen Belastungen von Müllwerkern zu erheben, wurde eine Bestandsaufnahme mit der Berufsgruppe vorgenommen, die Erkenntnisse für die spätere Beratungstätigkeit lieferte. Die Erhebung der Belastungen in Gruppendiskussionen wurde durch eine teilnehmende Beobachtung ergänzt, was einen psychodynamischen Blick auf die Besonderheiten der Organisation rund um den Müllwagen und die Charakteristika der Müllwerker erlaubte. Die Ergebnisse zeigen, dass ein Zusammenhang zwischen den Belastungen und dem beruflichen ...
Fourier Analysis of DG Schemes for Advection‐Diffusion
This work compares the wave propagation properties of discontinuous Galerkin (DG) schemes for advection‐diffusion problems in particular with respect to the discretization of diffusion terms. Extending previous investigations, the advection discretization now additionally varies between the choices of central or upwind fluxes. The results show that a previously recognized better performance of central schemes for well‐resolved problems only hold for even polynomial degrees and that upwind‐type discretizations also ...
The influence of magnetic field on nanoparticle transport in a micro channel
The present study focuses on a new solver considering the effect of magnetic field on nanoparticles concentration in a micro size channel. To describe the multi component behavior of blood, the Euler‐Euler method is used. Particles are modeled by a concentration equation considering a magnetic drift. The influence of a realistic magnetic field on nanoparticles is investigated. A result for a test case is presented. It shows that the magnetic body force resulting from nanoparticles also influence the hematocrit ...
Actuation of an elastic membrane by the use of an electrorheological valve
The dynamic response of a fluidic actuator is investigated on the basis of numerical simulations. With this actuator a membrane is excited to oscillate by means of an electrorheological valve. For this purpose the solid and fluid domains are coupled. Furthermore, the constitutive equation of the fluid is coupled to the electric field. The dynamic response is discussed on the example of a variable stiffness of the membrane. Actuators of this type offer the potential to delay the transition of a boundary layer.