Home  About us  Contact
 

Transition Elements (transition + element)

Distribution by Scientific Domains
Engineering75%

Selected Abstracts

Consistent coupling of beam and shell models for thermo-elastic analysis

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 14 2004
K. S. Chavan
Abstract In this paper, the finite element formulation of a transition element for consistent coupling between shell and beam finite element models of thin-walled beam-like structures in thermo-elastic problems is presented. Thin-walled beam-like structures modelled only with beam elements cannot be used to study local stress concentrations or to provide local mechanical or thermal boundary conditions. For this purpose, the structure has to be modelled using shell elements. However, computations using shell elements are a lot more expensive as compared to beam elements. The finite element model can be more efficient when the shell elements are used only in regions where the local effects are to be studied or local boundary conditions have to be provided. The remaining part of the structure can be modelled with beam elements. To couple these two models (i.e. shell and beam models) at transitional cross-sections, transition elements are derived here for thermo-elastic problems. The formulation encloses large displacement and rotational behaviour, which is important in case of thin-walled beam-like structures. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Polynomial basis functions on pyramidal elements

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 12 2008
M. J. Bluck
Abstract Pyramidal elements are necessary to effect the transition from tetrahedral to hexahedral elements, a common requirement in practical finite element applications. However, existing pyramidal transition elements suffer from degeneracy or other numerical difficulties, requiring, at the least, warnings and care in their use. This paper presents a general technique for the construction of nodal basis functions on pyramidal finite elements. General forms for basis functions of arbitrary order are presented. The basis functions so derived are fully conformal and free of degeneracy. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Consistent coupling of beam and shell models for thermo-elastic analysis

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 14 2004
K. S. Chavan
Abstract In this paper, the finite element formulation of a transition element for consistent coupling between shell and beam finite element models of thin-walled beam-like structures in thermo-elastic problems is presented. Thin-walled beam-like structures modelled only with beam elements cannot be used to study local stress concentrations or to provide local mechanical or thermal boundary conditions. For this purpose, the structure has to be modelled using shell elements. However, computations using shell elements are a lot more expensive as compared to beam elements. The finite element model can be more efficient when the shell elements are used only in regions where the local effects are to be studied or local boundary conditions have to be provided. The remaining part of the structure can be modelled with beam elements. To couple these two models (i.e. shell and beam models) at transitional cross-sections, transition elements are derived here for thermo-elastic problems. The formulation encloses large displacement and rotational behaviour, which is important in case of thin-walled beam-like structures. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Cation Leaching from the Basalt JB,1a by 2M NaCl Hydrothermal Solutions

RESOURCE GEOLOGY, Issue 2 2000
Etsuo UCHIDA
The experiments were carried out using standard cold-seal pressure vessels in the temperature range from 300 to 800C under the constant pressure of 1000 bars and also in the pressure range from 500 to 1000 bars at 600°C. The concentrations of Fe, Mn, Zn and Co in the hydrothermal solutions increased significantly with increasing temperature and with decreasing pressure. The thermodynamic analysis of the experimental results suggests that this is due to the formation of trichloro-complexes and also partly due to the temperature dependence of ion exchange between augite and aqueous chloride solution. The Na concentration in the aqueous solution decreases with increasing temperature and with decreasing pressure. On the other hand, the behavior of K, Ca and Mg is complex and their concentrations seem to be controlled by the coexisting minerals. Judging from the experimental results, it is concluded that the transition elements are effectively leached from the basalt under higher temperatures and lower pressures. This means that higher temperature and lower pressure conditions are preferable for the production of ore-forming hydrothermal solutions. [source]