TY - CHAP A1 - Kraft, Bodo A1 - Meyer, Oliver A1 - Nagl, Manfred T1 - Graph technology support for conceptual design in civil engineering N2 - In: Advances in intelligent computing in engineering : proceedings of the 9.International EG-ICE Workshop ; Darmstadt, (01 - 03 August) 2002 / Martina Schnellenbach-Held ... (eds.) . - Düsseldorf: VDI-Verl., 2002 .- Fortschritt-Berichte VDI, Reihe 4, Bauingenieurwesen ; 180 ; S. 1-35 The paper describes a novel way to support conceptual design in civil engineering. The designer uses semantical tools guaranteeing certain internal structures of the design result but also the fulfillment of various constraints. Two different approaches and corresponding tools are discussed: (a) Visually specified tools with automatic code generation to determine a design structure as well as fixing various constraints a design has to obey. These tools are also valuable for design knowledge specialist. (b) Extensions of existing CAD tools to provide semantical knowledge to be used by an architect. It is sketched how these different tools can be combined in the future. The main part of the paper discusses the concepts and realization of two prototypes following the two above approaches. The paper especially discusses that specific graphs and the specification of their structure are useful for both tool realization projects. KW - CAD KW - CAD ; KW - CAD KW - civil engineering Y1 - 2002 SN - 3-18-318004-9 ER - TY - CHAP A1 - Staat, Manfred A1 - Heitzer, Michael T1 - The restricted influence of kinematic hardening on shakedown loads N2 - Structural design analyses are conducted with the aim of verifying the exclusion of ratcheting. To this end it is important to make a clear distinction between the shakedown range and the ratcheting range. In cyclic plasticity more sophisticated hardening models have been suggested in order to model the strain evolution observed in ratcheting experiments. The hardening models used in shakedown analysis are comparatively simple. It is shown that shakedown analysis can make quite stable predictions of admissible load ranges despite the simplicity of the underlying hardening models. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis. Both give identical or similar shakedown ranges. Structural shakedown analyses show that the loading may have a more pronounced effect than the hardening model. KW - Biomedizinische Technik KW - Einspielen KW - Shakedown KW - Ratcheting KW - Bruchmechanik KW - shakedown KW - material shakedown KW - linear kinematic hardening KW - nonlinear kinematic hardening KW - ratchetting Y1 - 2002 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 - Dielmann, Klaus-Peter A1 - Peters, Bernhard T1 - Micro Turbine Using Different Gases and Liquid Fuels N2 - Micro turbine using different gases and liquid fuels KW - Gasturbine KW - Mikrogasturbine KW - Micro turbine Y1 - 2002 ER - TY - CHAP A1 - Chudoba, Rostislav A1 - Butenweg, Christoph A1 - Kuhlmann, Wolfram T1 - Technical information system for collaborative material research T2 - Sixth International Conference on Computational Structures Technology : [Prague, Czech Republic, 4 - 6 September 2002] Y1 - 2002 SP - 1 EP - 11 ER -