TY - CHAP A1 - Kern, Alexander A1 - Heidler, Fridolin A1 - Seevers, M. A1 - Zischank, Wolfgang J. T1 - Magnetic Fields and Induced Voltages in case of a Direct Strike - Comparison of Results obtained from Measurements at a Scaled Building to those of IEC 62305-4 N2 - In the paper the results obtained from experiments at a modelled reinforced building in case of a direct lightning strike are compared with calculations. The comparison includes peak values of the magnetic field Hmax, its derivative (dH/dt)max and of induced voltages umax in typical cable routings. The experiments are performed at a 1:6 scaled building and the results are extrapolated using the similarity relations theory. The calculations are based on the approximate formulae given in IEC 62305-4 and have to be supplemented by a rough estimation of the additional shielding effect of a second reinforcement layer. The comparison shows, that the measured peak values of the magnetic field and its derivative are mostly lower than the calculated. The induced voltages are in good agreement. Hence, calculations of the induced voltages based on IEC 62305-4 are a good method for lightning protection studies of buildings, where the reinforcement is used as a grid-like electromagnetic shield. N2 - Auswirkungen eines direkten Blitzeinschlages auf ein Gebäude, Vergleich von experimentellen Ergebnissen und Berechnungen basierend auf einer Formel aus der IEC 62305-4 KW - Blitz KW - Direkter Blitzschlag KW - Elektromagnetischer Schutzschild KW - Magnetische Felder KW - Induzierte Spannungen KW - Kalkulation KW - Direct lightning strike KW - electromagnetic shield KW - magnetic fields KW - induced voltages KW - calculations Y1 - 2004 SN - 0304-3886 N1 - Journal of electrostatics: Beitr. auf S. 379 - 385. doi:10.1016/j.elstat.2006.09.004 ER - TY - CHAP A1 - Zischank, Wolfgang J. A1 - Heidler, Fridolin A1 - Wiesinger, J. A1 - Stimper, K. A1 - Kern, Alexander A1 - Seevers, M. T1 - Magnetic Fields and Induced Voltages inside LPZ 1 Measured at a 1:6 Scale Model Building N2 - Laborexperimente zu Blitzschutzzonen in Stahlbetongebäuden anhand eines Modells im Maßstab 1:6 N2 - For the application of the concept of Lightning Protection Zones (LPZ), the knowledge of the magnetic fields and induced voltages inside a structure is necessary. Laboratory experiments have been conducted at a downscaled model of a building (scale factor 1:6) to determine these electromagnetic quantities in case of a direct strike to the structure. The model (3 m x 2 m x 2 m) represented a small industrial building using the reinforcement of the concrete as electromagnetic shield. The magnetic fields and magnetic field derivatives were measured at several location inside the scaled model. Further, the voltages induced on three typical cable routes inside the model was determined. The influence of the lightning current waveshape, point-of-strike, bonding of the cable routes, and bridging of an expansion joint in the middle of the building on these quantities was studied. KW - Blitzschlag KW - Elektromagnetischer Schutzschild KW - Stahlbeton KW - Maßstabsgetreues Modell KW - Lightning KW - electromagnetic shielding KW - reinforced concrete KW - scaled model Y1 - 2004 ER - TY - CHAP A1 - Darveniza, M. A1 - Flisowski, Z. A1 - Kern, Alexander A1 - Landers, E.-U. A1 - LoPiparo, G. A1 - Mazzetti, C. A1 - Rousseau, A. A1 - Sherlock, J. T1 - Application problems of the probabilistic approach to the assessment of risk for structures and services N2 - The paper deals with the development of the probabilistic approach to the assessment of risk due to lightning. Sources of damage, types of damage and types of loss are defined and, accordingly, the procedure for risk analysis and the way of assessment of different risk components is proposed. The way to evaluate the influence of different protection measures (lightning protection system; shielding of structure, cables and equipment; routing of internal wiring; surge protective device) in reducing such probabilities is considered. The paper has been prepared within the framework of the activity of IEC TC81-WG9/CLC TC81-WG4 directed to prepare the draft IEC 62305-2 Risk Management, in cooperation with the Secretary of IEC/CLC TC81. KW - Blitzschutz KW - Risikoabwägung KW - Lightning protection system KW - risk assessment KW - protection measures Y1 - 2002 ER - TY - CHAP A1 - Kern, Alexander A1 - Krichel, Frank T1 - Considerations about the lightning protection system of mains independent renewable energy hybrid-systems - practical experiences N2 - In the paper a lightning protection design concept for renewable energy hybrid-systems without power mains connection is described. Based on a risk analysis protection measures against direct strikes and overvoltages are shown in an overview. The design concept is realized exemplarily for the hybrid-system VATALI on the Greek island Crete. VATALI, not lightning protected at that time, was a victim of a lightning strike in the year 2000 causing destructions and damages of some mechanical and electrical components with costs of approx. 60.000 €. The hardware costs for the protection measures were about 15.000 €: about 50% of the costs are due to protection measures against direct strikes, 50% are due to overvoltage protection. KW - Blitzschutz KW - Erneuerbare Energien KW - Hybridsystem KW - Photovoltaikanlage KW - Windenergieanlage KW - Lightning protection KW - renewable energy KW - hybrid system KW - photovoltaic system KW - wind turbine Y1 - 2002 ER - TY - CHAP A1 - Zischank, Wolfgang J. A1 - Heidler, Fridolin A1 - Kern, Alexander A1 - Metwally, I. A. A1 - Wiesinger, J. A1 - Seevers, M. T1 - Laboratory simulation of direct lightning strokes to a modelled building - measurement of magnetic fields and induced voltages N2 - In IEC 61312-2 equations for the assessment of the magnetic fields inside structures due to a direct lightning strike are given. These equations are based on computer simulations for shields consisting of a single-layer steel grid of a given mesh width. Real constructions, however, contain at least two layers of reinforcement steel grids. The objective of this study was to experimentally determine the additional shielding effectiveness of a second reinforcement layer compared to a single-layer grid. To this end, simulated structures were set up in the high current laboratory. The structures consisted of cubic cages of 2 m side length with one or with two reinforcement grids, respectively. The structures were exposed to direct lightning currents representing the variety of anticipated lightning current waveforms. The magnetic fields and their derivatives at several positions inside the structure as well as the voltage between “floor” and “roof” in the center were determined for different current injection points. From these data the improvement of the shielding caused by a second reinforcement layer is derived. KW - Direkter Blitzschlag KW - Elektromagnetischer Schutzschild KW - Magnetische Felder KW - Induzierte Spannungen KW - Stahlbetonkonstruktion KW - Lightning KW - electromagnetic shielding KW - magnetic field KW - reinforced concrete KW - induced voltage Y1 - 2002 ER - TY - CHAP A1 - Ritz, Thomas T1 - Personalized information services : an electronic information commodity and its production T2 - Electronic publishing '01 : 2001 in the digital publishing odyssey ; proceedings of an ICCC/IFIP conference held at the University of Kent at Canterbury, Kent, United Kingdom, 5 - 7 July, 2001 ; [proceedings of the Fifth Conference on Electronic Publishing] Y1 - 2001 SN - 1-58603-191-0 SP - 48 EP - 58 PB - IOS Press [u.a.] CY - Amsterdam ER - TY - CHAP A1 - Ritz, Thomas T1 - DISMED - an innovation portal for printing and media industry T2 - CRIS 2000 : the fifth conference on Current Research Information Systems in Europe, in Helsinki (Finland), 25-27 May 2000 Y1 - 2001 N1 - Programmpunkt: Cybercafé. PB - CORDIS Archive CY - [s.l.] ER - TY - CHAP A1 - Ritz, Thomas T1 - Production and distribution of personalized information services employing mass customization T2 - 2nd Interdisciplinary World Congress on Mass Customization and Personalization : MCPC'03, October 6 - 8, 2003, Technische Universität München, Munic, Germany Y1 - 2003 SP - Part IV PB - Techn. Univ. (TUM) CY - München ET - CD-Ausg. ER - TY - CHAP A1 - Stender, Michael A1 - Ritz, Thomas T1 - Modeling of business-to-business mobile commerce processes T2 - Electronic proceedings / ICPR 17, 17th International Conference on Production Research [Blacksburg, Virginia, USA, August 3 - 7, 2003] Y1 - 2003 SN - 0-9721257-3-6 CY - Blacksburg, Va. ET - CD-ROM-Ausg. ER - TY - CHAP A1 - Staat, Manfred A1 - Heitzer, Michael T1 - Limit and shakedown analysis for plastic design N2 - Limit and shakedown theorems are exact theories of classical plasticity for the direct computation of safety factors or of the load carrying capacity under constant and varying loads. Simple versions of limit and shakedown analysis are the basis of all design codes for pressure vessels and pipings. Using Finite Element Methods more realistic modeling can be used for a more rational design. The methods can be extended to yield optimum plastic design. In this paper we present a first implementation in FE of limit and shakedown analyses for perfectly plastic material. Limit and shakedown analyses are done of a pipe–junction and a interaction diagram is calculated. The results are in good correspondence with the analytic solution we give in the appendix. KW - Einspielen KW - Traglast KW - Finite-Elemente-Methode KW - Traglastanalyse KW - Einspielanalyse KW - FEM KW - limit analysis KW - shakedown analysis Y1 - 1997 ER -