Brassard, P., Seifert, T., Secher, N. H.
Background Vasopressor agents are commonly used to increase mean arterial pressure (MAP) in order to secure a pressure gradient to perfuse vital organs. The influence of norepinephrine on cerebral...
The present paper focuses on the application of line-search methods in general return mapping algorithms. Two inexact line-search methods and an exact line-search method are investigated regarding...
The present paper focuses on the consistent linearization and finite element implementation of an incrementally objective canonical form return mapping algorithm. A general and modular algorithmic...
Rechnerische Methoden zur Lebensdauervorhersage von gegossenen Hochtemperaturbauteilen (2008)
Eisengusswerkstoffe weisen aufgrund der Graphitausscheidungen ein asymmetrisches Verhalten in Zug und Druck auf. Es wurde ein Werkstoffmodell entwickelt, das die Fähigkeiten des Chaboche Modells und...
Seifert, T., Schenk, T., Schmidt, I.
This paper presents a general algorithmic formulation for constitutive equations describing inelastic material deformation. The algorithmic representation focuses on the generality and modularity...
Korrelation zwischen zyklischer Rissspitzenöffnung und Lebensdauer (2007)
Schweizer, C., Seifert, T., Schlesinger, M., Riedel, H.
Under LCF and TMF loading the lifetime is often determined by the growth of microcracks, which generally nucleate during the first cycles. Assuming the crack growth rate per cycle to be approximately...
Schenk, T., Seifert, T., Brehm, H.
Cyclic stress-strain measurements have to be performed in order to determine the cyclic plasticity parameters of material models describing the Bauschinger effect. For thin wires, the performance of...
Fatigue life simulation for optimized exhaust manifold geometry (2006)
Mohrmann, R., Seifert, T., Willeke, W., Hartmann, D.
Modern exhaust systems must withstand servere cyclic mechanical and thermal loads throughout the whole life cycle. Growing demands on designs targeted at reliability and cost optimization require new...
Zur Modellierung des viskoplastischen Werkstoffverhaltens mit fortschrittlichen Stoffgesetzen unter niederfrequenter Ermüdungsbelastung (low-cycle fatigue, LCF) sind Daten zum einen aus zyklischen...
Tandler, M., Seifert, T., Mohrmann, R.
Der Eindruckversuch hat das Potential quais-zerstörungsfrei lokale Werkstoffeigenschaften direkt am Bauteil zu messen. Am Fraunhofer-Institut für Werkstoffmechanik wird eine Methode entwickelt, um...
Thermo-mechanical material models for components of engines and power plants (2006)
Seifert, T., Mohrmann, R., Hartrott, P. Von, Tandler, M., Riedel, H.
In this paper material models are presented that have been developed at the Fraunhofer Institute for Mechanics of Materials (IWM) for thermo-mechanical applications. One the one hand deformation...
Anpassung eines nicht-isothermen Verformungsmodells an X12CrMoWVNbN 10-1-1 (2006)
Hartrott, P. Von, Schlesinger, M., Seifert, T., Mohrmann, R.
Die nachfrageorientierte Produktion elektrischer Energie in konventionellen Kraftwerken erhöht die Zahl der An- und Abfahrvorgänge. Der für die Lebensdauer eines Hochtemperaturbauteils...
Im Automobilbau, in der Kraftwerkstechnik und im allgemeinen Maschinenbau erweisen sich Bauteile, die nicht isothermen Belastungen ausgesetzt sind, immer dann als kritisch, wenn die Grenzen der rein...
Modelling the TMF-life of a salt bath experiment with viscoplastic constitutive equations (2005)
Mohrmann, R., Seifert, T., Höll, H.
The salt bath experiment was chosen because of the load characteristics. It is simple enough to allow treatment at moderate cost while containing a geometrical concentration of stress subject to...
Grote, R., Patzner, K., Seifert, T.
Gnauck, A. [Hrsg.]
Wiberg, N., Amelunxen, K., Lerner, H. W., Schuster, H., Noeth, H., Krossing, I., ...
Supersilyl alk. metals (alkali supersilanides) tBu3SiM without or with donors (Do) like ethers, amines, arom. hydrocarbons are easily obtained by the action of alk. metals M on supersilyl halides...
Systematik zur Bewertung von F&E-Projekten (1996)
Niemeier, J., Schwenkenbecher, K., Smandek, B., Seifert, T.
Der sich weltweit verschärfende Wettbewerb erzwingt eine rigerose Ergebnisorientierung bei der Initierung und Durchführung von F&E-Projekten. Gerade für kleine und mittelständische...
Eisenberger Ringfixateur. Ein neuentwickeltes Ringfixationssystem (1996)
Weber, C., Seifert, T., Ahnert, H., Damm, C., Guyenot, V.
External fixation devices are regularly by orthopaedists and traumatologists for treatment of bone fractures, bone defects as well as for bone lengthening. This new design is a conceptual adaption...
High resolution spherical grid topography of the Baltic Sea (1995)
Meereswissenschaftliche Berichte, ISSN 0939-396X, nr. 9, 72-88
AUZENDE, JM, HALBACH, P, ALLSPACH, A, BECKER, K, BLUM, N, BONNIER, O, ...
AUZENDE, JM, HALBACH, P, ALLSPACH, A, BECKER, K, BLUM, N, BONNIER, O, ...
On the dynamics of upwelling observed at the Darss Sill (1994)
Lass, H.U., Schmidt, T., Seifert, T.
Proc. of 19. Conference of Baltic Oceanographers. Gdansk, Poland, August 29th to September 1st, 1994. Vol. 1, 247-260
Fully automated angle resolved scatterometer (1994)
The ARS-scatterometer at the IOF Jena which has been designed and built in cooperation with the Carl Zeiss JENA GmbH is capable of performing accurate measurements of the BRDF over a range of...
The signal-averaged ECG: Time-domain analysis (1993)
Breithardt, G., Wichter, T., Fetsch, T., Seifert, T., Borggrefe, M., Shenasa, M., ...
During the past decade, the high-resolution electrocardiogram as a non-invasive technique for the detection of ventricular late potentials has developed from an experimental method into a routinely...
Rossby radii and phase speeds in the Baltic Sea (1991)
Fennel, W., Seifert, T., Kayser, B.
Continental shelf research, ISSN 0278-4343, vol. 11, nr. 1, 23 - 36
Acute small subcortical infarctions on diffusion weighted MRI: clinical presentation and aetiology
Seifert, T, Enzinger, C, Storch, M, Pichler, G, Niederkorn, K, Fazekas, F
Objective: To determine the clinical presentation and aetiology of small subcortical infarctions as found on diffusion weighted magnetic resonance imaging (DWI). DWI is both sensitive and specific in...