Bierwisch, C., Kraft, T., Riedel, H., Moseler, M.
Rapid granular flow from a moving container and angle of repose formation were investigated by numerical simulations using the discrete element method (DEM) and experiments. Grain models of various...
A. Radocaj, T. Weiss, W. Helsby, B. Brenner, T. Kraft
Journal article
Three-dimensional discrete element models for the granular statics and dynamics of powders (2009)
Moseler, M., Bierwisch, C., Kraft, T., Riedel, H.
A novel coarse graining scheme for the discrete element method (DEM) was developed which allows for the representation of a given granular system using artificially enlarged grains. Based on the...
Wonisch, A., Kraft, T., Moseler, M., Riedel, H.
Simulations based on the discrete element method (DEM) are used to investigate the relationship between the distribution of particle sizes and the macroscopic sintering behavior of ceramic powders....
Simulation in powder technology, in (2008)
This chapter describes micromechanical and macroscopic material models for granular and porous materials and applications to powder technological processing steps. The emphasis lies on powder...
Shining light on structural states of actomyosin cross-bridges (2008)
A. Radocaj, T. Weiss, W. Helsby, B. Brenner, ...
Contribution to a conf. proceeding (journal)
Produktdesign von Pressgranulaten: Anforderungen und Realität (2008)
Nebelung, M., Fries, M., Kraft, T.
Das Ziel einer Granulatentwicklung ist eine Materialschüttung mit homogenem, reproduzierbarem Fließverhalten und exzellenten Verdichtungseigenschaften, um eine homogene Verteilung der...
Simulation of die filling in 3D with special emphasis on vibration supported filling (2008)
Bierwisch, C., Kraft, T., Moseler, M., Riedel, H.
Modelling die filling with focus on density distribution is a key component in establishing a continuous virtual process chain for the die compaction and sintering processing route. A discrete...
Finite element modelling of PM surface densification process (2008)
Yazici, B.A., Kraft, T., Riedel, H.
The developments in the field of powder metallurgy (PM) enable production of complex shapes in a cost competitive way especially for automotive industry. Surface densification of sintered gears...
Discrete element simulations of constrained ceramic powder sintering (2008)
Wonisch, A., Kraft, T., Moseler, M., Riedel, H.
A particle-based simulation approach employing the discrete element method (DEM) is presented for ceramic powder sintering under geometric constraints. The grain-scale approach allows investigating...
Numerical homogenisation of elasto-plastic granule assemblies using discretised particles (2008)
Schmidt, I., Kraft, T., Riedel, H.
In this contribution, the finite element method is used to investigate the deformation mechanisms in- and the macroscopic response of an assembly comprised of elasto-plastic spherical granules....
Simulations of the influence of rearrangement during sintering (2007)
Henrich, B., Wonisch, A., Kraft, T., Moseler, M., Riedel, H.
A three-dimensional application of the discrete element method to free, constrained and pressure-assisted solid-state sintering of powders is presented. Special emphasis is laid on the generation of...
Stress-induced anisotropy of sintering alumina: Discrete element modelling and experiments (2007)
Wonisch, A., Guillon, O., Kraft, T., Moseler, M., Riedel, H., Rödel, J.
Simulations based on the discrete element method are employed to investigate the anisotropic sintering of alumina. The results are compared with accompanying experiments. It is shown that during...
A. Radocaj, T. Weiss, W. Helsby, T. Kraft, ...
Contribution to a conf. proceeding (journal)
Simulation von Prozessfolgen mit der Diskrete-Elemente-Methode (2007)
Riedel, H., Wonisch, A., Bierwisch, C., Kraft, T., Moseler, M.
Finite-Elemente basierte Methoden sind gut geeignet, um Herstellungsprozesse von Bauteilen auch mit komplexen Formen zu modellieren. In der Zwischenzeit wurden die Simulationsmöglichkeiten durch die...
Towards an Earthquake Monitoring System for Indian Ocean Tsunami Early Warning (2006)
Kraft, T., Hanka, W., Saul, J., Heinloo, A., Reinhardt, J., Weber, B., ...
Wonisch, A., Korn, K., Kraft, T., Riedel, H.
Sintering green bodies made by typical industrial production processes like uniaxial compaction, tape casting or extrusion may exhibit a significant anisotropic microstructure, which in turn leads to...
Multi-scale simulations of rearrangement effects and anisotropic behavior during sintering (2006)
Wonisch, A., Kraft, T., Riedel, H.
Numerical modeling of sintering by continuum mechanical simulations is successfully applied today to predict e.g. the distortions developing during sintering. Several examples that demonstrate the...
Borchert, D., Riepe, S., Kübler, R., Beinert, J., Kraft, T., Kleer, G., ...
The influence of the thermal treatment during the saw damage etching process on the mechanical stability of multicrystalline silicon wafers has been investigated for four different alkaline saw...
E. Maehlmann, T. Mattei, B. Piep, B. Brenner, ...
Contribution to a conf. proceeding (journal)
A. Radocaj, T. Weiss, W. Helsby, B. Brenner, ...
Contribution to a conf. proceeding (journal)
Coube, O., Jonsén, P., Kraft, T., Chen, Y., Imbault, D., Doremus, P., ...
Keramische Walzwerkzeuge aus Siliciumnitrid zur Herstellung von Drähten, Rohren und Bändern (2005)
Kailer, A., Hollstein, T., Pfeiffer, W., Kraft, T.
Im Rahmen eines Verbundprojekts wurden keramische Walzen für verschiedene Anwendungen konzipiert, hergestellt und unter Einsatzbedingungen getestet. Ziel dieser Untersuchungen war zunächst der...
Simulations in powder technology at Fraunhofer IWM (2005)
During the last fifteen years, the Powder Technology Research Group of the IWM h as worked on the simulation of various processing steps in powder technology. The list of materials studied comprises...
Simulation von Rissbildung und Verzug in der Mikroelektronik (2005)
Kraft, T., Riedel, H., Schwanke, D., Müller, E.
Ein wesentlicher Prozessschritt bei der Herstellung von keramischen Mehrlagenschaltungen ist das Sintern. Beim Sintern bildet sich unter dem Einfluss hoher Temperatur aus dem vorgeformten Grünling...
Multi-scale modeling and simulation of sintering (2005)
Kraft, T., Henrich, B., Moseler, M., Riedel, H.
Simulation methods to study sintering based on finite elements as well as discrete particle dynamics are presented. Both methods have their application focus on different length scales. The particle...
Modelling and simulation of processing steps in powder technology using particle dynamics (2005)
Kraft, T., Henrich, B., Bierwisch, C., Moseler, M., Riedel, H.
A simulation method based on discrete particle dynamics is presented and applied to die filling, compaction and sintering. The method is computationally very efficient so that three dimensional...
Modelling of anisotropic shrinkage during liquid phase sintering (2005)
Korn, K., Kraft, T., Riedel, H.
Green bodies made by tape casting, extrusion or uniaxial die compaction may ehib it appreciable sintering anisotropy. To account for this, a micromechanical liquid phase sintering model was extended...
Coube, O., Jonsén, P., Kraft, T., Chen, Y., Imbault, D., Doremus, P., ...
The paper describes a simulation of the compaction of a two level part manufactured from a ferrous powder that was completed as a benchmark within the Dienet Thematic Network. The simulations confirm...
Computer simulation as a tool in PM material science and technology (2005)
Kraft, T., Riedel, H., Gumbsch, P.
This article describes the simulation of different powder technological processing steps. Among many routes the die compaction processing route is selcted as a demonstration example. From the process...
3D-modeling of die filling (2005)
Bierwisch, C., Henrich, B., Kraft, T., Moseler, M., Riedel, H.
Using three-dimensional meso-particle dynamics (MPD) simulations we investigate die filling processes. In contrast to continuum methods this approach automatically takes into account the...
Beinert, J., Kübler, R., Kordisch, H., Könczöl, L., Kraft, T., Kleer, G.
Silicon is brittle and fragile but also expensive. Because many steps in indust rial PV production processes involve mechanical or thermal stresses, fracturing can be initiated during manufacturing...
Initiation of the power stroke in muscle: Insights from the phosphate analog AlF4 (2005)
T. Kraft, E. Maehlmann, T. Mattei, B. Brenner
Journal article
Numerical simulation of solid state sintering: Model and application (2004)
A comprehensive model for solid state sintering is presented which combines several previous models for partial aspects of sintering and grain coarsening. Some additional aspects are discussed and...
Assessment of fatigue lifetime of PM-parts (2004)
For predicting the fatigue lifetime of a P/M component not only the loading history must be considered, but also the porosity distribution, which can influence the material behaviour significantly...
Simulation in powder technology (2004)
This chapter describes micromechanical and macroscopic material models for granular and porous materials and applications to powder technological processing steps. The emphasis lies on powder...
Reiterer, M., Kraft, T., Riedel, H.
Sinter forming is a recently developed process for the production of advanced ceramic components. It combines pressure-supported sintering and superplastic deformation, and allows RBAO (Reaction...
Finite element simulation of cold isostatic pressing and sintering of SiC components (2004)
Reiterer, M., Kraft, T., Janosovits, U., Riedel, H.
Finite element simulations were performed for cold isostatic pressing of SiC powder. To describe the compaction behaviour, the Drucker-Prager-Cap model implemented in ABAQUS/Explicit® computer...
Optimale pulvertechnologische Bauteile durch Simulation (2003)
Seit Jahrtausenden ist der pulvertechnologische Herstellungsprozess Töpfern bekannt. In jüngerer Zeit werden zunehmend hochspezialisierte und komplexe Strukturbauteile aus den verschiedensten...
Compaction and sintering of a ceramic seal: Modeling and experimental response (2003)
Kraft, T., Riedel, H., Rosenfelder, O.
The delivery time of a new powder-metallurgical component is controlled by the tooling design, manufacture and commissioning. Cracking of the part in the production process must be avoided, and close...
Designing, manufacturing and commissioning of the tooling often determines the delivery time of a new powder-metallurgical component. To speed-up this process, computer simulations of die compaction...
To predict the fatigue lifetime of a P/M component not only the loading history must be considered, but also the porosity distribution, which can influence the material behavior significantly and...
Prediction of fatigue lifetime of PM-parts (2003)
For predicting the fatigue lifetime of a P/M component not only the loading history must be considered, but also the porosity distribution, which can influence the material behavior significantly and...
Designing, manufacturing and commissioning of the tooling often determines the delivery time of a new powder-metallurgical component. To speed-up this process, computer simulations of die compaction...
Mutation of the myosin converter domain alters cross-bridge elasticity (2002)
Köhler, J., Winkler, G., Schulte, I., Scholz, T., McKenna, W., Brenner, B., ...
Elastic distortion of a structural element of the actomyosin complex is fundamental to the ability of myosin to generate motile forces. An elastic element allows strain to develop within the...
Numerical simulation of die compaction and sintering (2002)
A method to simulate die compaction and sintering is presented. By implementing user defined routines for both processes into the general purpose finite element program ABAQUS quantitative...
Distortions and cracking of graded components during sintering (1999)
The aim of the project is to develop methods for predicting distortions and cracking during the fabrication of gradient materials, and to apply them to simple geometries (tubes, beams and plates)....
Wendler, L., Kraft, T., Hartung, M., Berger, A., Wixforth, A., Sundaram, M., ...
Grating-coupler-induced collective intersubband transitions in a quasi-two-dimensional electron system are investigated both experimentally and theoretically. Far-infrared transmission experiments...
Elastic properties of strained fcc and hcp iron (1993)
Kraft, T., Methfessel, M., Van Schilfgaarde, M., Scheffler, M., Oppeneer, P. M., Kübler, J.
Kraft, T., Zinsmeister, K., Meijer, H.A.J., Hotop, H.
We describe a straightforward and accurate method for the frequency stabilization of two dye lasers on frequencies ν01 and ν02, fitting two atomic transitions from the ground state to the first...
Absolute detection of metastable rare gas atoms by a cw laser photoionization method (1991)
Hotop, H., Smith, S.J., Schmitz, U., Meijer, H.A.J., Kraft, T., ...
A novel, accurate method for the absolute detection of metastable rare gas atoms is described and demonstrated. It involves a direct in situ determination of the electron emission coefficient γ for...
Kraft, T, Yu, L C, Kuhn, H J, Brenner, B
In the presence of the nucleotide analog adenosine 5'-[gamma-thio]triphosphate (ATP[gamma S]), effects of Ca2+ on stiffness and equatorial x-ray diffraction patterns of single skinned fibers of the...
Xu, S, Malinchik, S, Gilroy, D, Kraft, T, Brenner, B, Yu, L C
X-ray diffraction patterns were obtained from skinned rabbit psoas muscle under relaxing and rigor conditions over a wide range of ionic strengths (50-170 mM) and temperatures (1 degree C-30 degrees...
Force enhancement without changes in cross-bridge turnover kinetics: the effect of EMD 57033.
The thiadiazinon derivative EMD 57033 has been found previously in cardiac muscle to increase isometric force generation without a proportional increase in fiber ATPase, thus causing a reduction in...
Heubach, J F, Hartwell, R, Ledwon, M, Kraft, T, Brenner, B, Chalovich, J M
Several regions within the 35-kDa COOH-terminal portion of caldesmon have been implicated in the ability of caldesmon to inhibit actin-activated myosin ATPase activity. To further define the...
Brenner, B, Kraft, T, DasGupta, G, Reisler, E
To assess the significance of the NH2-terminus of actin for cross-bridge action in muscle, skinned fibers of rabbit psoas muscle were equilibrated with Fab fragments of antibodies directed against...
Kraft, T, Messerli, M, Rothen-Rutishauser, B, Perriard, J C, Wallimann, T, Brenner, B
Confocal laser fluorescence microscopy was used to study in real time under nearly physiological conditions the equilibration and exchange characteristics of several different fluorescently labeled...
Kraft, T, Chalovich, J M, Yu, L C, Brenner, B
Previously we showed that stiffness of relaxed fibers and active force generated in single skinned fibers of rabbit psoas muscle are inhibited in parallel by actin-binding fragments of caldesmon, an...
Kraft, T, Xu, S, Brenner, B, Yu, L C
To study possible structural changes in weak cross-bridge attachment to actin upon activation of the thin filament, two-dimensional (2D) x-ray diffraction patterns of skinned fibers from rabbit psoas...
Brenner, B, Kraft, T, Yu, LC, Chalovich, JM
A method is described for the exchange of native troponin of single rabbit psoas muscle fibers for externally applied troponin complexes without detectable impairment of functional properties of the...
Kraft, T, Säll, T, Magnusson-Rading, I, Nilsson, N O, Halldén, C
The relation between the level of genetic variation and the rate of recombination per physical unit was investigated in sea beet (Beta vulgaris subsp. maritima). The rate of recombination per...
Kraft, T, Yu, L C, Kuhn, H J, Brenner, B
In the presence of the nucleotide analog adenosine 5'-[gamma-thio]triphosphate (ATP[gamma S]), effects of Ca2+ on stiffness and equatorial x-ray diffraction patterns of single skinned fibers of the...
Xu, S, Malinchik, S, Gilroy, D, Kraft, T, Brenner, B, Yu, L C
X-ray diffraction patterns were obtained from skinned rabbit psoas muscle under relaxing and rigor conditions over a wide range of ionic strengths (50-170 mM) and temperatures (1 degree C-30 degrees...
Force enhancement without changes in cross-bridge turnover kinetics: the effect of EMD 57033.
The thiadiazinon derivative EMD 57033 has been found previously in cardiac muscle to increase isometric force generation without a proportional increase in fiber ATPase, thus causing a reduction in...
Heubach, J F, Hartwell, R, Ledwon, M, Kraft, T, Brenner, B, Chalovich, J M
Several regions within the 35-kDa COOH-terminal portion of caldesmon have been implicated in the ability of caldesmon to inhibit actin-activated myosin ATPase activity. To further define the...
Brenner, B, Kraft, T, DasGupta, G, Reisler, E
To assess the significance of the NH2-terminus of actin for cross-bridge action in muscle, skinned fibers of rabbit psoas muscle were equilibrated with Fab fragments of antibodies directed against...
Kraft, T, Messerli, M, Rothen-Rutishauser, B, Perriard, J C, Wallimann, T, Brenner, B
Confocal laser fluorescence microscopy was used to study in real time under nearly physiological conditions the equilibration and exchange characteristics of several different fluorescently labeled...
Kraft, T, Chalovich, J M, Yu, L C, Brenner, B
Previously we showed that stiffness of relaxed fibers and active force generated in single skinned fibers of rabbit psoas muscle are inhibited in parallel by actin-binding fragments of caldesmon, an...
Kraft, T, Xu, S, Brenner, B, Yu, L C
To study possible structural changes in weak cross-bridge attachment to actin upon activation of the thin filament, two-dimensional (2D) x-ray diffraction patterns of skinned fibers from rabbit psoas...
Brenner, B, Kraft, T, Yu, LC, Chalovich, JM
A method is described for the exchange of native troponin of single rabbit psoas muscle fibers for externally applied troponin complexes without detectable impairment of functional properties of the...
Kraft, T, Säll, T, Magnusson-Rading, I, Nilsson, N O, Halldén, C
The relation between the level of genetic variation and the rate of recombination per physical unit was investigated in sea beet (Beta vulgaris subsp. maritima). The rate of recombination per...