The safety of large civil structures is often evaluated by means of numerical models based on the Finite Element Method. In this frame, the choice of a constitutive law able to represent the complex mechanical behaviour of concrete is a key point. This paper deals with a detail description of all the steps needed to implement the Microplane Model in COMSOL; the formulation is based on the ...
M. Bachmann, V. Avilov, A. Gumenyuk, and M. Rethmeier
BAM Federal Institute for Materials Research and Testing
The article deals with the magnetically-supported high-power full-penetration laser beam welding of aluminum. A stationary simulation was conducted accounting for the effects of natural convection, Marangoni convection and solid-liquid phase transition as well as an electromagnetic volume source term. An ac magnet below the weld specimen induces eddy currents. Consequently, Lorentz forces occur ...
H. Ye, E. M. Boudoudou, E. Scholz, and M. Clemens
Chair of Electromagnetic Theory
Bergische Universität Wuppertal
For PE insulated cables both the temperature difference ?T and the electric field coefficient ? have a significant influence on the electric field distribution because PE has a nonlinear electric conductivity which is approximately a function of the temperature and the electric field strength. The coupled electric-thermal simulations are carried out for PE insulated HVDC-cables. The influence ...
E. Holzbecher, P. Oberdorfer, F. Maier, and Y. Jin
Georg-August Universität Göttingen
Geothermal heat production from deep reservoirs (5000-7000 m) is currently examined, not only in Germany. Our reference set-up consists of two pipes within a single borehole: one for pumping. We examine a design, where a single borehole splits into two legs at a certain depth. The two legs are connected by highly permeable geological, natural or artificial strata in the deep subsurface. The ...
M. Hackert-Oschätzchen, S. F. Jahn, and A. Schubert
Chemnitz University of Technology
The principle of electrochemical machining (ECM) is the anodic dissolution of a metallic workpiece at the interface to a liquid ionic conductor under the influence of electric charge transport. This erosion principle works independently from the mechanical hardness of the workpiece and is free of mechanical forces. The design of electrochemical machining processes is still performed ...
Y. Jin, E. Holzbecher, and P. Oberdorfer
A novel method for groundwater lowering, which can be applied at construction sites, for aquifer remediation measures or in open mining, is proposed. In contrast to conventional techniques, dewatering is achieved without water conveyance. In this paper the physical concept of the new technology, referred as single borehole pump & inject, is modeled using COMSOL Multiphysics. Two and three ...
O. Fritz, M. Ljuslinder, and B. Doser
ABB Switzerland Ltd, Corporate Research, Baden-Dättwil, Switzerland
ABB Switzerland Ltd, High Voltage Products, Wettingen, Switzerland
We present examples of the use of COMSOL Multiphysics for the solution of electrical conduction in varistors coupled to the solution of long-term heat-transport through conduction and convection. We fit measured power-loss and impedance data with analytic functions in order to simulate instant electric and transient thermal processes in one go. We systematically compare our results to data ...
E. Amores, J. Rodriguez Ruiz, C. Merino Rodríguez, and P. García Escribano
Centro Nacional del Hidrógeno
The production of hydrogen from renewable energy surplus is seen as a key strategy for energy storage. Centro Nacional del Hidrógeno works actively in this direction by considering a strategic line in order to achieve a sustainable energy future. Alkaline electrolysis is the main industrial way of obtaining hydrogen by electrolysis. However, commercial alkaline electrolyzers are designed for ...
Numerical Analysis of Propeller-induced Low-frequency Modulations in Underwater Electric Potential Signatures of Naval Vessels in the Context of Corrosion Protection Systems
D. Schaefer, J. Doose, A. Rennings, and D. Erni
General and Theoretical Electrical Engineering (ATE), Faculty of Engineering, University of Duisburg-Essen, Duisburg, Germany
Technical Center for Ships and Naval Weapons (WTD 71), Bundeswehr, Eckernförde, Germany
Since October 2009 the laboratory of ATE has carried out collaborative research with the WTD 71 that aims for prediction, reduction and optimization of so-called underwater electric potential (UEP) signatures. COMSOL is used to simulate potential distributions in the context of impressed current cathodic protection (ICCP) systems. The electrode kinetics is considered by using boundary conditions ...
H. Lissek, R. Boulandet, and M. Maugard
Ecole Polytechnique Federale de Lausanne
An \"electroacoustic absorber\" is a loudspeaker, used as an absorber of sound, which acoustic impedance can be varied by electrical means. This can be achieved either by plugging passive shunt electric networks at the loudspeaker terminals (“shunt loudspeakers”) or by feeding back the loudspeaker with a voltage proportional to acoustic quantities, such as sound pressure and diaphragm normal ...