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Past earthquakes demonstrated the high vulnerability of industrial facilities equipped with complex process technologies leading to serious damage of the process equipment and multiple and simultaneous release of hazardous substances in industrial facilities. Nevertheless, the design of industrial plants is inadequately described in recent codes and guidelines, as they do not consider the dynamic interaction between the structure and the installations and thus the effect of seismic response of the installations on the response of the structure and vice versa. The current code-based approach for the seismic design of industrial facilities is considered not enough for ensure proper safety conditions against exceptional event entailing loss of content and related consequences. Accordingly, SPIF project (Seismic Performance of Multi- Component Systems in Special Risk Industrial Facilities) was proposed within the framework of the European H2020 - SERA funding scheme (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe). The objective of the SPIF project is the investigation of the seismic behavior of a representative industrial structure equipped with complex process technology by means of shaking table tests. The test structure is a three-story moment resisting steel frame with vertical and horizontal vessels and cabinets, arranged on the three levels and connected by pipes. The dynamic behavior of the test structure and installations is investigated with and without base isolation. Furthermore, both firmly anchored and isolated components are taken into account to compare their dynamic behavior and interactions with each other. Artificial and synthetic ground motions are applied to study the seismic response at different PGA levels. After each test, dynamic identification measurements are carried out to characterize the system condition. The contribution presents the numerical simulations to calibrate the tests on the prototype, the experimental setup of the investigated structure and installations, selected measurement data and finally describes preliminary experimental results.
Seismic excited liquid filled tanks are subjected to extreme loading due to hydrodynamic pressures, which can lead to nonlinear stability failure of the thinwalled cylindrical tanks, as it is known from past earthquakes. A significant reduction of the seismically induced loads can be obtained by the application of base isolation systems, which have to be designed carefully with respect to the modified hydrodynamic behaviour of the tank in interaction with the liquid. For this reason a highly sophisticated fluid-structure interaction model has to be applied for a realistic simulation of the overall dynamic system. In the following, such a model is presented and compared with the results of simplified mathematical models for rigidly supported tanks. Finally, it is examined to what extent a simple mechanical model can represent the behaviour of a base isolated tank in case of seismic excitation
Seismic design of buried pipeline systems for energy and water supply is not only important for plant and operational safety but also for the maintenance of the supply infrastructure after an earthquake. The present paper shows special issues of the seismic wave impacts on buried pipelines, describes calculation methods, proposes approaches and gives calculation examples. This paper regards the effects of transient displacement differences and resulting tensions within the pipeline due to the wave propagation of the earthquake. However, the presented model can also be used to calculate fault rupture induced displacements. Based on a three-dimensional Finite Element Model parameter studies are performed to show the influence of several parameters such as incoming wave angle, wave velocity, backfill height and synthetic displacement time histories. The interaction between the pipeline and the surrounding soil is modeled with non-linear soil springs and the propagating wave is simulated affecting the pipeline punctually, independently in time and space. Special attention is given to long-distance heat pipeline systems. Here, in regular distances expansion bends are arranged to ensure movements of the pipeline due to high temperature. Such expansion bends are usually designed with small bending radii, which during the earthquake lead to high bending stresses in the cross-section of the pipeline. Finally, an interpretation of the results and recommendations are given for the most critical parameters.
Industrial facilities must be thoroughly designed to withstand seismic actions as they exhibit an increased loss potential due to the possibly wideranging damage consequences and the valuable process engineering equipment. Past earthquakes showed the social and political consequences of seismic damage to industrial facilities and sensitized the population and politicians worldwide for the possible hazard emanating from industrial facilities. However, a holistic approach for the seismic design of industrial facilities can presently neither be found in national nor in international standards. The introduction of EN 1998-4 of the new generation of Eurocode 8 will improve the normative situation with
specific seismic design rules for silos, tanks and pipelines and secondary process components. The article presents essential aspects of the seismic design of industrial facilities based on the new generation of Eurocode 8 using the example of tank structures and secondary process components. The interaction effects of the process components with the primary structure are illustrated by means of the experimental results of a shaking table test of a three story moment resisting steel frame with different process components. Finally, an integrated approach of
digital plant models based on building information modelling (BIM) and structural health monitoring (SHM) is presented, which provides not only a reliable decision-making basis for operation, maintenance and repair but also an excellent tool for rapid assessment of seismic damage.
Reinforced concrete (RC) structures with masonry infills are widely used for several types of buildings all over the world. However, it is well known that traditional masonry infills constructed with rigid contact to the surrounding RC frame performed rather poor in past earthquakes. Masonry infills showed severe in-plane damages and failed in many cases under out-of-plane seismic loading. As the undesired interactions between frames and infills changes the load transfer on building level, complete collapses of buildings were observed. A possible solution is uncoupling of masonry infills to the frame to reduce the infill contribution activated by the frame deformation under horizontal loading. The paper presents numerical simulations on RC frames equipped with the innovative decoupling system INODIS. The system was developed within the European project INSYSME and allows an effective uncoupling of frame and infill. The simulations are carried out with a micro-modelling approach, which is able to predict the complex nonlinear behaviour resulting from the different materials and their interaction. Each brick is modelled individually and connected taking into account nonlinearity of a brick mortar interface. The calibration of the model is based on small specimen tests and experimental results for one bay one storey frame are used for the validation. The validated model is further used for parametric studies on two storey and two bay infilled frames. The response and change of the structural stiffness are analysed and compared to the traditionally infilled frame. The results confirm the effectiveness of the INODIS system with less damage and relatively low contribution of the infill at high drift levels. In contrast to the uncoupled system configurations, traditionally infilled frames experienced brittle failure at rather low drift levels.
Risk management for structures with a risk of explosion should be considered very carefully when performing a risk analysis according to IEC 62305-2. In contrast to the 2006 edition of the standard, the 2010 edition describes the topic “Structures with a risk of explosion” in more detail. Moreover, in Germany separate procedures and parameters are defined for the risk analysis of structures with a risk of explosion (Supplement 3 of the German DIN EN 62305-2 standard). This paper describes the contents and the relevant calculations of this Supplement 3, together with a numerical example.
Die neue Vornorm VDE V 0185 Teil 2 „Risikomanagement: Abschätzung des Schadensrisikos für bauliche Anlagen“ [1] ist seit November 2002 gültig. Sie ermöglicht nicht nur die Ermittlung der Schutzklasse eines Blitzschutzsystems, sondern auch die Untersuchung zur Notwendigkeit anderer Schutzmaßnahmen gegen Blitzeinwirkungen (Überspannungsschutzgeräte in Unterverteilern und/oder an Endgeräten, Schirmung des Gebäudes und/oder interner Räume, Potentialsteuerung, Brandmelde- und Feuerlöscheinrichtungen, etc.) nach objektiven Kriterien und damit in einer für alle Beteiligten grundsätzlich nachvollziehbaren Art und Weise. Dass eine solche Analyse rel. komplex sein muss und der intensiven Beschäftigung bedarf, ist deshalb nicht verwunderlich. Die Komplexität des Verfahrens sollte allerdings nicht dazu führen, die Vornorm als Ganzes abzulehnen. Die Vornorm beruht auf dem Stand der Diskussion im internationalen Normengremium IEC TC81 WG9 Ende des Jahres 2000. Integriert wurden einige nationale Besonderheiten, die aus Sicht des zuständigen Normenkomitees DKE K251 erforderlich erschienen. In Deutschland konnten und können nun erste breite Erfahrungen in der Anwendung dieser Risikoanalyse gesammelt werden; in anderen Ländern ist dies noch nicht möglich. Diese Erfahrungen können dann, nach Diskussion im nationalen Rahmen, in die internationale Normenarbeit eingebracht werden. Im folgenden Beitrag sollen einige, seit Erscheinen der Vornorm oft wiederkehrende Fragen dargestellt und Lösungsvorschläge vorgestellt werden. Dabei wird auch auf die Tendenzen im internationalen Normengremium IEC TC81 WG9 eingegangen, d.h. auf den aktuellen Entwurf zur IEC 62305-2 [3]. Die Lösungsvorschläge werden begründet, sind allerdings weitestgehend subjektive Meinung des Autors. Für übliche bauliche Anlagen ist die Anwendung der Vornorm rel. einfach möglich. Auch für spezielle Fälle können die darin festgelegten Verfahren herangezogen werden; allerdings sind dann einige weiterführende Überlegungen notwendig, die der Planer von Blitzschutzsystemen durchführen muss. Anhand zweier Beispiele soll die Anwendung der VDE V 0185 Teil 2 auf solche speziellen Fälle dargestellt werden.
Alle Unternehmen sind vielfältigen Risiken ausgesetzt, die Finanz- und Betriebsbereiche einschließlich Dienstleistungen betreffen können. Die Firmen müssen üblicherweise Risiken eingehen, um im Wettbewerb bestehen zu können. Entscheidend ist, dass man sich über die Risiken bewusst ist, diese einschätzen und kontrollieren kann. Falsche Einschätzungen, Versäumnisse und Fehlentscheidungen können empfindliche finanzielle Schäden bis hin zum Totalverlust nach sich ziehen. Ein effektives Risikomanagement ist heute als wichtiger Sicherheitsfaktor anzusehen und sollte zur strategischen Unternehmensführung gehören. Ein vorausschauendes Risikomanagement beinhaltet, Risiken für das Unternehmen zu kalkulieren. Es liefert Entscheidungsgrundlagen, um diese Risiken zu begrenzen und es macht transparent, welche Risiken sinnvollerweise über Versicherungen abgedeckt werden sollten. Beim Versicherungsmanagement ist jedoch zu bedenken, dass zur Erreichung bestimmter Ziele Versicherungen nicht geeignet sind (z.B. Erhaltung der Lieferfähigkeit). Eintrittswahrscheinlichkeiten bestimmter Risiken lassen sich durch Versicherungen nicht verändern. Bei Unternehmen, die mit umfangreichen elektronischen Einrichtungen produzieren oder Dienstleistungen erbringen (und das sind heutzutage wohl die meisten), muss auch das Risiko durch Blitzeinwirkungen besondere Berücksichtigung finden. Dabei ist zu beachten, dass der Schaden aufgrund der Nicht-Verfügbarkeit der elektronischen Einrichtungen und damit der Produktion bzw. der Dienstleistung und ggf. der Verlust von Daten den Hardware-Schaden an der betroffenen Anlage oft bei weitem übersteigt. Im Blitzschutz gewinnt innovatives Denken in Schadensrisiken langsam an Bedeutung. Risikoanalysen haben die Objektivierung und Quantifizierung der Gefährdung von baulichen Anlagen und ihrer Inhalte durch direkte und indirekte Blitzeinschläge zum Ziel. Seinen Niederschlag hat dieses neue Denken in der neuen deutschen Norm DIN V 0185-2 VDE V 0185 Teil 2 gefunden. Die hier vorgegebene Risikoanalyse gewährleistet, dass ein für alle Beteiligten nachvollziehbares Blitzschutz-Konzept erstellt werden kann, das technisch und wirtschaftlich optimiert ist, d.h. bei möglichst geringem Aufwand den notwendigen Schutz gewährleisten kann. Die sich aus der Risikoanalyse ergebenden Schutzmaßnahmen sind dann in den weiteren Normenteilen der neuen Reihe VDE V 0185 detailliert beschrieben.
Seismic vulnerability estimation of existing structures is unquestionably interesting topic of high priority, particularly after earthquake events. Having in mind the vast number of old masonry buildings in North Macedonia serving as public institutions, it is evident that the structural assessment of these buildings is an issue of great importance. In this paper, a comprehensive methodology for the development of seismic fragility curves of existing masonry buildings is presented. A scenario – based method that incorporates the knowledge of the tectonic style of the considered region, the active fault characterization, the earth crust model and the historical seismicity (determined via the Neo Deterministic approach) is used for calculation of the necessary response spectra. The capacity of the investigated masonry buildings has been determined by using nonlinear static analysis. MINEA software (SDA Engineering) is used for verification of the structural safety of the structures Performance point, obtained from the intersection of the capacity of the building and the spectra used, is selected as a response parameter. The thresholds of the spectral displacement are obtained by splitting the capacity curve into five parts, utilizing empirical formulas which are represented as a function of yield displacement and ultimate displacement. As a result, four levels of damage limit states are determined. A maximum likelihood estimation procedure for the process of fragility curves determination is noted as a final step in the proposed procedure. As a result, region specific series of vulnerability curves for structures are defined.
In the presented paper data collected from the field related to damage statistics of electrical and electronic apparatus in household are reported and investigated. These damages (total number approx. 74000 cases), registered by five German insurance companies in 2005 and 2006, were adviced by customers as caused by lightning overvoltages. With the use of stochastical methods it is possible, to reasses the collected data and to distinguish between cases, which are with high probability caused by lightning overvoltages, and those, which are not. If there was an indication for a direct strike, this case was excluded, so the focus was only on indirect lightning flashes, i.e. only flashes to ground near the structure and flashes to or nearby an incoming service line were investigated. The data from the field contain the location of damaged apparatus (residence of the policy holder) and the distances of the nearest cloud-to-ground stroke to the location of the damage registered by the German lightning location network BLIDS at the date of damage. The statistical data along with some complementary numerical simulations allow to verify the correspondence of the Standards rules used for IEC 62305-2 with the field data and to define some correction needs. The results could lead to a better understanding whether a damage reported to an insurance company is really caused by indirect lightning, or not.
The Ministry of Science and Research in North Rhine-Westphalia created eight platforms of excellence, one in the research area „Energy and Environment“ in 2002 at ACUAS. This platform concentrates the research and development of 13 professors in Jülich and Aachen and of two scientific institutes with different topics: – NOWUM-Energy with emphasis on efficient and economic energy conversion – The Solar Institute Jülich – SIJ – being the largest research institute in the field of renewables at a University of Applied Sciences in Germany With this platform each possible energy conversion – nuclear, fossil, renewable- can be dealt with to help solving the two most important problems of mankind, energy and potable water. At the CSE are presented the historical development, some research results and the combined master studies in „Energy Systems“ and „Nuclear Applications“
Plasma-Spritzen
(1991)
Masonry is used in many buildings not only for load-bearing walls, but also for non-load-bearing enclosure elements in the form of infill walls. Many studies confirmed that infill walls interact with the surrounding reinforced concrete frame, thus changing dynamic characteristics of the structure. Consequently, masonry infills cannot be neglected in the design process. However, although the relevant standards contain requirements for infill walls, they do not describe how these requirements are to be met concretely. This leads in practice to the fact that the infill walls are neither dimensioned nor constructed correctly. The evidence of this fact is confirmed by the recent earthquakes, which have led to enormous damages, sometimes followed by the total collapse of buildings and loss of human lives. Recently, the increasing effort has been dedicated to the approach of decoupling of masonry infills from the frame elements by introducing the gap in between. This helps in removing the interaction between infills and frame, but raises the question of out-of-plane stability of the panel. This paper presents the results of the experimental campaign showing the out-of-plane behavior of masonry infills decoupled with the system called INODIS (Innovative decoupled infill system), developed within the European project INSYSME (Innovative Systems for Earthquake Resistant Masonry Enclosures in Reinforced Concrete Buildings). Full scale specimens were subjected to the different loading conditions and combinations of in-plane and out-of-plane loading. Out-of-plane capacity of the masonry infills with the INODIS system is compared with traditionally constructed infills, showing that INODIS system provides reliable out-of-plane connection under various loading conditions. In contrast, traditional infills performed very poor in the case of combined and simultaneously applied in-plane and out-of-plane loading, experiencing brittle behavior under small in-plane drifts followed by high out-of-plane displacements. Decoupled infills with the INODIS system have remained stable under out-of-plane loads, even after reaching high in-plane drifts and being damaged.
As part of the transnational research project EDITOR, a parabolic trough collector system (PTC) with concrete thermal energy storage (C-TES) was installed and commissioned in Limassol, Cyprus. The system is located on the premises of the beverage manufacturer KEAN Soft Drinks Ltd. and its function is to supply process steam for the factory's pasteurisation process [1]. Depending on the factory's seasonally varying capacity for beverage production, the solar system delivers between 5 and 25 % of the total steam demand. In combination with the C-TES, the solar plant can supply process steam on demand before sunrise or after sunset. Furthermore, the C-TES compensates the PTC during the day in fluctuating weather conditions. The parabolic trough collector as well as the control and oil handling unit is designed and manufactured by Protarget AG, Germany. The C-TES is designed and produced by CADE Soluciones de Ingeniería, S.L., Spain. In the focus of this paper is the description of the operational experience with the PTC, C-TES and boiler during the commissioning and operation phase. Additionally, innovative optimisation measures are presented.
The planned coal phase-out in Germany by 2038 will lead to the dismantling of power plants with a total capacity of approx. 30 GW. A possible further use of these assets is the conversion of the power plants to thermal storage power plants; the use of these power plants on the day-ahead market is considerably limited by their technical parameters. In this paper, the influence of the technical boundary conditions on the operating times of these storage facilities is presented. For this purpose, the storage power plants were described as an MILP problem and two price curves, one from 2015 with a relatively low renewable penetration (33 %) and one from 2020 with a high renewable energy penetration (51 %) are compared. The operating times were examined as a function of the technical parameters and the critical influencing factors were investigated. The thermal storage power plant operation duration and the energy shifted with the price curve of 2020
increases by more than 25 % compared to 2015.
We present first results from a newly developed monitoring station for a closed loop geothermal heat pump test installation at our campus, consisting of helix coils and plate heat exchangers, as well as an ice-store system. There are more than 40 temperature sensors and several soil moisture content sensors distributed around the system, allowing a detailed monitoring under different operating conditions.In the view of the modern development of renewable energies along with the newly concepts known as Internet of Things and Industry 4.0 (high-tech strategy from the German government), we created a user-friendly web application, which will connect the things (sensors) with the open network (www). Besides other advantages, this allows a continuous remote monitoring of the data from the numerous sensors at an arbitrary sampling rate.Based on the recorded data, we will also present first results from numerical simulations, taking into account all relevant heat transport processes.The aim is to improve the understanding of these processes and their influence on the thermal behavior of shallow geothermal systems in the unsaturated zone. This will in turn facilitate the prediction of the performance of these systems and therefore yield an improvement in their dimensioning when designing a specific shallow geothermal installation.
This paper describes the procedure on the evaluation of the masonry chapter for the next generation of Eurocode 8, the European Standard for earthquake-resistant design. In CEN, TC 250/SC8, working group WG 1 has been established to support the subcommittee on the topic of masonry on both design of new structures (EN1998-1) and assessment of existing structures (EN1998-3). The aim is to elaborate suggestions for amendments which fit the current state of the art in masonry and earthquake-resistant design. Focus will be on modelling, simplified methods, linear-analysis (q-values, overstrength-values), nonlinear procedures, out-of-plane design as well as on clearer definition of limit states. Beside these, topics related to general material properties, reinforced masonry, confined masonry, mixed structures and non-structural infills will be covered too. This paper presents the preliminary work and results up to the submission date.
New coupled finite-infinite element approach for wave propagation simulation of unbounded soil media
(2014)
Im Projekt Coolplan‐ AIR geht es um die Fortentwicklung und Feld‐ Validierung eines Berechnungs‐ und Auslegungstools zur energieeffizienten Kühlung von Gebäuden mit luftgestützten Systemen. Neben dem Aufbau und der Weiterentwicklung von Simulationsmodellen erfolgen Vermessungen der Gesamtsysteme anhand von Praxisanlagen im Feld. Eine der betrachteten Anlagen arbeitet mit indirekter Verdunstung. Diese Veröffentlichung zeigt den Entwicklungsprozess und den Aufbau des Simulationsmodells zur Verdunstungskühlung in der Simulationsumgebung Matlab‐ Simulink mit der CARNOT‐ Toolbox. Das besondere Augenmerk liegt dabei auf dem physikalischen Modell des Wärmeübertragers, in dem die Verdunstung implementiert ist. Dem neuen Modellansatz liegt die Annahme einer aus der Enthalpie‐ Betrachtung hergeleiteten effektiven Wärmekapazität zugrunde. Des Weiteren wird der Befeuchtungsgrad als konstant angesehen und eine standardisierte Zunahme der Wärmeübertragung des feuchten gegenüber dem trockenen Wärmeübertrager angenommen. Die Validierung des Modells erfolgte anhand von Literaturdaten. Für den trockenen Wärmetauscher ist der maximale absolute Fehler der berechneten Austrittstemperatur (Zuluft) kleiner als ±0.1 K und für den nassen Wärmetauscher (Kühlfall) unter der Annahme eines konstanten Verdunstungsgrades kleiner als ±0.4 K.
Im Rahmen eines modernen Blitzschutzsystems für Stahlbeton-Bauten bietet es sich an, die Betonbewehrung zu benutzen: - Sie kann die Funktionen der Ableitungseinrichtungen und des Blitzschutz- Potentialausgleichs bei einem klassischen Gebäude-Blitzschutz übernehmen [1]; - Sie kann, ggf. bei entsprechender Ergänzung, als ein geschlossener Käfig ausgebildet werden und damit eine deutliche Reduzierung der Belastung elektrischer / elektronischer Systeme durch blitzinduzierte elektromagnetische Felder erbringen (LEMP-Schutz [2]). Die Nutzung der Bewehrung ist dabei grundsätzlich gleichermaßen bei Neubauten wie auch bei Ertüchtigungen möglich und sinnvoll. So stellt die Nutzung der Bewehrung beispielsweise im Bereich von Großkraftwerken eine wesentliche Ertüchtigungsmaßnahme für den Blitzschutz elektrischer und elektronischer Einrichtungen dar: - Einerseits wird der Blitzschutz-Potentialausgleich durch den Anschluss metallener Einrichtungen wie Elektronik-Schränke, Kabeltrag-Konstruktionen, Rohrleitungen, etc. an die Bewehrung deutlich verbessert. - Andererseits kann bei größeren Gebäuden die elektromagnetische Schirmwirkung durch die elektrische Überbrückung von vorhandenen Dehnfugen bei Stahlbetonbauten optimiert werden. Diese Dehnfugen sind teilweise nur unzureichend überbrückt, so dass bei Blitzeinschlag in das betreffende oder ein benachbartes Gebäude an Kabelstrecken, die über die Dehnfuge hinwegführen, rel. hohe Spannungen induziert werden können [2, 3]. Die sich um das gesamte Gebäude herumziehende oder zwischen zwei Gebäuden befindliche Dehnfuge muss deshalb im Abstand von maximal einigen Metern überbrückt werden. Im Falle von Blitzschutz-Ertüchtigungen in vorhandenen Gebäuden wird bisher an jeder geplanten Anschlussstelle die Bewehrung großflächig (∅ wenige 10 cm) freigelegt, dort ein elektrischer Anschluss zu dem Bewehrungsstab hergestellt, z.B. mittels eines Erdungsfestpunkts, und dann die Betonoberfläche wieder geschlossen. Je nach prognostizierter Strombelastung wird teilweise versucht, den über den Anschluss fließenden Strom bereits auf mehrere Bewehrungsstäbe zu verteilen. Dazu sind entweder die kreuzenden Stäbe zu verschweißen oder es sind direkt Anschlüsse an zwei Bewehrungsstäbe herzustellen. All dieses bedeutet einen hohen Aufwand bei der Freilegung der Bewehrung und auch wieder bei der Schließung der entstandenen Betonlöcher. Es soll deshalb hier untersucht werden, ob es beispielsweise zum Zwecke des Blitzschutz-Potentialausgleichs und auch zur Überbrückung von Dehnfugen ausreichend ist, den Anschluss an die Bewehrung nach einfachen Verfahren nur jeweils an einen Bewehrungsstab herzustellen. Damit würde der finanzielle und administrative Aufwand an Betonarbeiten deutlich reduziert. Die hier dargestellten Verfahren sind dabei insbesondere für den Einsatz bei Blitzschutz-Ertüchtigungen in bestehenden Gebäuden vorgesehen. Abschließend sollen deshalb die Möglichkeiten zur Prüfung korrekter Anschlüsse, die Grenzen der Verfahren sowie auch die Grenzen der Anwendbarkeit bei Neuanlagen diskutiert werden.
Neue Möglichkeiten der Klebstoffverarbeitung durch geschwindigkeitsproportionalen Handauftrag
(2006)
Multi-dimensional fragility analysis of a RC building with components using response surface method
(2017)
Conventional fragility curves describe the vulnerability of the main structure under external hazards. However, in complex structures such as nuclear power plants, the safety or the risk depends also on the components associated with a system. The classical fault tree analysis gives an overall view of the failure and contains several subsystems to the main event, however, the interactions in the subsystems are not well represented. In order to represent the interaction of the components, a method suggested by Cimellaro et al. (2006) using multidimensional performance limit state functions to obtain the system fragility curves is adopted. This approach gives the possibility of deriving the cumulative fragility taking into account the interaction of the response of different components. In this paper, this approach is used to evaluate seismic risk of a representative electrical building infrastructure, including the component, of a nuclear power plant. A simplified model of the structure, with nonlinear material behavior is employed for the analysis in Abaqus©. The input variables considered are the material parameters, boundary conditions and the seismic input. The variability of the seismic input is obtained from selected ground motion time histories of spectrum compatible synthetic ccelerograms. Unlike the usual Monte Carlo methods used for the probabilistic analysis of the structure, a computationally effective response surface method is used. This method reduces the computational effort of the calculations by reducing the required
number of samples.
The future of industrial manufacturing and production will increasingly manifest in the form of cyber-physical production systems. Here, Digital Shadows will act as mediators between the physical and digital world to model and operationalize the interactions and relationships between different entities in production systems. Until now, the associated concepts have been primarily pursued and implemented from a technocentric perspective, in which human actors play a subordinate role, if they are considered at all. This paper outlines an anthropocentric approach that explicitly considers the characteristics, behavior, and traits and states of human actors in socio-technical production systems. For this purpose, we discuss the potentials and the expected challenges and threats of creating and using Human Digital Shadows in production.
Concentrated Solar Power (CSP) systems are able to store energy cost-effectively in their integrated thermal energy storage (TES). By intelligently combining Photovoltaics (PV) systems with CSP, a further cost reduction of solar power plants is expected, as well as an increase in dispatchability and flexibility of power generation. PV-powered Resistance Heaters (RH) can be deployed to raise the temperature of the molten salt hot storage from 385 °C up to 565 °C in a Parabolic Trough Collector (PTC) plant. To avoid freezing and decomposition of molten salt, the temperature distribution in the electrical resistance heater is investigated in the present study. For this purpose, a RH has been modeled and CFD simulations have been performed. The simulation results show that the hottest regions occur on the electric rod surface behind the last baffle. A technical optimization was performed by adjusting three parameters: Shell-baffle clearance, electric rod-baffle clearance and number of baffles. After the technical optimization was carried out, the temperature difference between the maximum temperature and the average outlet temperature of the salt is within the acceptable limits, thus critical salt decomposition has been avoided. Additionally, the CFD simulations results were analyzed and compared with results obtained with a one-dimensional model in Modelica.
Modeling and upscaling of a pilot bayonettube reactor for indirect solar mixed methane reforming
(2020)
A 16.77 kW thermal power bayonet-tube reactor for the mixed reforming of methane using solar energy has been designed and modeled. A test bench for the experimental tests has been installed at the Synlight facility in Juelich, Germany and has just been commissioned. This paper presents the solar-heated reactor design for a combined steam and dry reforming as well as a scaled-up process simulation of a solar reforming plant for methanol production. Solar power towers are capable of providing large amounts of heat to drive high-endothermic reactions, and their integration with thermochemical processes shows a promising future. In the designed bayonet-tube reactor, the conventional burner arrangement for the combustion of natural gas has been substituted by a continuous 930 °C hot air stream, provided by means of a solar heated air receiver, a ceramic thermal storage and an auxiliary firing system. Inside the solar-heated reactor, the heat is transferred by means of convective mechanism mainly; instead of radiation mechanism as typically prevailing in fossil-based industrial reforming processes. A scaled-up solar reforming plant of 50.5 MWth was designed and simulated in Dymola® and AspenPlus®. In comparison to a fossil-based industrial reforming process of the same thermal capacity, a solar reforming plant with thermal storage promises a reduction up to 57 % of annual natural gas consumption in regions with annual DNI-value of 2349 kWh/m2. The benchmark solar reforming plant contributes to a CO2 avoidance of approx. 79 kilotons per year. This facility can produce a nominal output of 734.4 t of synthesis gas and out of this 530 t of methanol a day.
Despite the challenges of pioneering molten salt towers (MST), it remains the leading technology in central receiver power plants today, thanks to cost effective storage integration and high cost reduction potential. The limited controllability in volatile solar conditions can cause significant losses, which are difficult to estimate without comprehensive modeling [1]. This paper presents a Methodology to generate predictions of the dynamic behavior of the receiver system as part of an operating assistance system (OAS). Based on this, it delivers proposals if and when to drain and refill the receiver during a cloudy period in order maximize the net yield and quantifies the amount of net electricity gained by this. After prior analysis with a detailed dynamic two-phase model of the entire receiver system, two different reduced modeling approaches where developed and implemented in the OAS. A tailored decision algorithm utilizes both models to deliver the desired predictions efficiently and with appropriate accuracy.
Seismic behavior of an existing unreinforced masonry building built pre-modern code, located in the City of Ohrid, Republic of North Macedonia has been investigated in this paper. The analyzed school building is selected as an archetype in an ongoing project named “Seismic vulnerability assessment of existing masonry structures in Republic of North Macedonia (SeismoWall)”. Two independent segments were included in this research: Seismic hazard assessment by creating a cite specific response spectra and Seismic vulnerability definition by creating a region - specific series of vulnerability curves for the chosen building topology. A reliable Seismic Hazard Assessment for a selected region is a crucial point for performing a seismic risk analysis of a characteristic building class. In that manner, a scenario – based method that incorporates together the knowledge of tectonic style of the considered region, the active fault characterization, the earth crust model and the historical seismicity named Neo Deterministic approach is used for calculation of the response spectra for the location of the building. Variations of the rupturing process are taken into account in the nucleation point of the rupture, in the rupture velocity pattern and in the istribution of the slip on the fault. The results obtained from the multiple scenarios are obtained as an envelope of the response spectra computed for the cite using the procedure Maximum Credible Seismic Input (MCSI). Capacity of the selected building has been determined by using nonlinear static analysis. MINEA software (SDA Engineering) was used for verification of the structural safety of the chosen unreinforced masonry structure. In the process of optimization of the number of samples, computational cost required in a Monte Carlo simulation is significantly reduced since the simulation is performed on a polynomial response surface function for prediction of the structural response. Performance point, found as the intersection of the capacity of the building and the spectra used, is chosen as a response parameter. Five levels of damage limit states based on the capacity curve of the building are defined in dependency on the yield displacement and the maximum displacement. Maximum likelihood estimation procedure is utilized in the process of vulnerability curves determination. As a result, region specific series of vulnerability curves for the chosen type of masonry structures are defined. The obtained probabilities of exceedance a specific damage states as a result from vulnerability curves are compared with the observed damages happened after the earthquake in July 2017 in the City of Ohrid, North Macedonia.
In times of social climate protection movements, such as Fridays for Future, the priorities of society, industry and higher education are currently changing. The consideration of sustainability challenges is increasing. In the context of sustainable development, social skills are crucial to achieving the United Nations Sustainable Development Goals (SDGs). In particular, the impact that educational activities have on people, communities and society is therefore coming to the fore. Research has shown that people with high levels of social competence are better able to manage stressful situations, maintain positive relationships and communicate effectively. They are also associated with better academic performance and career success. However, especially in engineering programs, the social pillar is underrepresented compared to the environmental and economic pillars.
In response to these changes, higher education institutions should be more aware of their social impact - from individual forms of teaching to entire modules and degree programs. To specifically determine the potential for improvement and derive resulting change for further development, we present an initial framework for social impact measurement by transferring already established approaches from the business sector to the education sector. To demonstrate the applicability, we measure the key competencies taught in undergraduate engineering programs in Germany.
The aim is to prepare the students for success in the modern world of work and their future contribution to sustainable development. Additionally, the university can include the results in its sustainability report. Our method can be applied to different teaching methods and enables their comparison.
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.
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.
Lightning protection design of a renewable energy hybrid-system without power mains connection
(2001)
In the year 2000 a direct lightning strike to the hybridsystem without power mains connection VATALI on the Greek island Crete results in the destruction and damage of some mechanical and electrical components. The hybrid-system VATALI was not lightning protected at that time. The hardware damage costs are approx. 60,000 €. The exposed site of the hybrid-system on top of a mountain was and still is the reason for a high risk of lightning strikes. Also in the future further lightning strikes have to be taken into consideration. In the paper a fundamental lightning protection design concept for renewable energy hybrid-systems without power mains connection and protection measures against direct strikes and overvoltages are shown in detail. The design concept was realized exemplarily for the hybrid-system VATALI. 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. Future extensions, new installations, or modifications have to be included into the lightning protection design concept of the hybrid-system.
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.
Kompakter Aufbau eines lichtadressierbaren potentiometrischen Sensors mit verfahrbarem Diodenlaser
(2011)
Investigation Of The Seismic Behaviour Of Infill Masonry Using Numerical Modelling Approaches
(2017)
Masonry is a widely spread construction type which is used all over the world for different types of structures. Due to its simple and cheap construction, it is used as non-structural as well as structural element. In frame structures, such as
reinforced concrete frames, masonry may be used as infill. While the bare frame itself is able to carry the loads when it comes to seismic events, the infilled frame is not able to warp freely due to the constrained movement. This restraint results in a complex interaction between the infill and the surrounding frame, which may lead to severe damage to the infill as well as the surrounding frame. The interaction is studied in different projects and effective approaches for the description of the behavior are still lacking. Experimental programs are usually quite expensive, while numerical models, once validated, do offer an efficient approach for the investigation of the interaction when horizontally loaded. In order to study the numerous parameters influencing the seismic load bearing behavior, numerical models may be used. Therefore, this contribution presents a numerical approach for the simulation of infill masonry in reinforced concrete frames. Both parts, the surrounding frame as well as the infill are represented by micro modelling approaches to correctly take into account the different types of failure. The adopted numerical model describes the inelastic behavior of the system, as indicated by the obtained results of the overall structural response as well as the formation of damage in the infilled wall. Comparison of the numerical and experimental results highlights the valuable contribution of numerical simulations in the study and design of infilled frames. As damage of the infill masonry may occur in-plane due to the interaction as well as out-of-plane due to the low vertical load, both directions of loading are investigated.
The seismic performance and safety of major European industrial facilities has a global interest for Europe, its citizens and economy. A potential major disaster at an industrial site could affect several countries, probably far beyond the country where it is located. However, the seismic design and safety assessment of these facilities is practically based on national, often outdated seismic hazard assessment studies, due to many reasons, including the absence of a reliable, commonly developed seismic hazard model for whole Europe. This important gap is no more existing, as the 2020 European Seismic Hazard Model ESHM20 was released in December 2021. In this paper we investigate the expected impact of the adoption of ESHM20 on the seismic demand for industrial facilities, through the comparison of the ESHM20 probabilistic hazard at the sites where industrial facilities are located with the respective national and European regulations. The goal of this preliminary work in the framework of Working Group 13 of the European Association for Earthquake Engineering (EAEE), is to identify potential inadequacies in the design and safety control of existing industrial facilities and to highlight the expected impact of the adoption of the new European Seismic Hazard Model on the design of new industrial facilities and the safety assessment of existing ones.
New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work.
As an interdisciplinary research network, the Cluster of Excellence “Integrative Production Technology for High-Wage Countries” (CoE) comprises of around 150 researchers. Their scientific background ranges from mechanical engineering and computer science to social sciences such as sociology and psychology. In addition to content- and methodbased challenges, the CoE’s employees are faced with heterogenic organizational cultures, different hierarchical levels, an imbalanced gender distribution, and a high employee fluctuation. The sub-project Scientific Cooperation Engineering 1 (CSP1) addresses the challenge of interdisciplinary cooperation and organizational learning and aims at fostering interdisciplinarity and its synergies as a source of innovation. Therefore, the project examines means of reaching an organizational development, ranging from temporal structures to a sustainable network in production technology. To achieve this aim, a broad range of means has been developed during the last twelve years: In addition to physical measures such as regular network events and trainings, virtual measures such as the Terminology App were focused. The app is an algorithmic analysis method for uncovering latent topic structures of publications of the CoE to highlight thematic intersections and synergy potentials. The detection and promotion of has been a vital and long known element in knowledge management. Furthermore, CSP1 focusses on project management and thus developed evaluation tools to measure and control the success of interdisciplinary cooperation. In addition to the cooperation fostering measures, CSP1 conducted studies about interdisciplinarity and diversity and their relationship with innovation. The scientific background of these means and the research results of CSP1 are outlined in this paper to offer approaches for successful interdisciplinary cooperation management.
Nowadays modern high-performance buildings and facilities are equipped with monitoring systems and sensors to control building characteristics like energy consumption, temperature pattern and structural safety. The visualization and interpretation of sensor data is typically based on simple spreadsheets and non-standardized user-oriented solutions, which makes it difficult for building owners, facility managers and decision-makers to evaluate and understand the data. The solution of this problem in the future are integrated BIM-Sensor approaches which allow the generation of BIM models incorporating all relevant information of monitoring systems. These approaches support both the dynamic visualization of key structural performance parameters, the effective long-term management of sensor data based on BIM and provide a user-friendly interface to communicate with various stakeholders. A major benefit for the end user is the use of the BIM software architecture, which is the future standard anyway. In the following, the application of the integrated BIM-Sensor approach is illustrated for a typical industrial facility as a part of an early warning and rapid response system for earthquake events currently developed in the research project “ROBUST” with financial support by the German Federal Ministry for Economic Affairs and Energy (BMWI).
Acknowledging that a diverse workforce could be a potential source of innovation, the current research deals with the fine details of why diversity management is central to achieving innovation in heterogeneous research groups and how this could be effectively realized in an organization. The types of heterogeneities addressed mainly include gender, qualification, academic discipline and intercultural perspectives. The type of organization being dealt with in this work is a complex association of research institutes at a technical university in Germany (RWTH Aachen University), namely a 'Cluster of Excellence', whereby several institutes of the university work collaboratively in different sub-projects. The 'Cluster of Excellence' is a part of the 'Excellence Initiative' of the German federal and state governments German Research Foundation (DFG) and German Council of Science and Humanities, with the ultimate aim of promoting cutting-edge research. To support interdisciplinary collaboration and thus the performance of the cluster, the development of a diversity and innovation management concept is presently in the conceptual phase and will be described in the frame of this paper. The 3-S-Diversity Model, composed of the three elements: skills, structure and strategy, serves as a basis for the development of the concept. The proposed concept consists of six phases; the first two phases lay the ground work by developing an understanding of the status quo on the forms of diversity in the Cluster of Excellence, the type of organizational structure of the member institutes and the varieties of specialist work cultures of the same. The third and the fourth phases build up on this foundation by means of qualitative and quantitative studies. While the third phase deals with the sensitization of the management level to the close connection between diversity and innovation; the need to manage them thereafter and find tailor-made methods of doing so, the fourth phase shall mainly focus on the mindset of the employees in this regard. The fifth phase shall consolidate the learnings and the ideas developed in the course of the first four phases into an implementable strategy. The ultimate phase shall be the implementation of this concept in the Cluster. The first three phases have been accomplished successfully and the preliminary results are already available.
The link between diversity and innovation is broadly discussed in the context of research and innovation processes. Many institutions and enterprises, specifically in commerce, have already tried to establish sustainable diversity management concepts, in order to increase the diversity of their workforce in addition to establishing a corporate culture of openness. Alongside the creation of a working place where different experiences and skills are valued equally, the entrepreneurial intention is to transfer diversity into economically relevant advantages. Taking into account the potential of diversity in research and innovation processes, the project “Diversity- and Innovation Management” was incorporated within a large interdisciplinary research Cluster. The project’s purpose was to study the context between diversity and innovation in research associations and to later develop a customised management concept into an interdisciplinary research Cluster on integrative production technology with full integration. The challenge of such research associations lays in an organisational structure which is often described as being decentralised. Researchers coming from different academic disciplines, while having diverse habits, conduct research on large scientific issues and challenges. In addition, these researchers are socialised in different institutions and university chairs. Theses differences in leadership styles, business cultures and organisational strategies, follow into their research team work. Taking a closer look into the management of human resources suggests that decentral organised recruitment processes, as well as allocation of human resources, lead to a lacking overview in regard to missing competencies, perspectives and backgrounds in research networks. These circumstances are comparable to big corporate groups. While developing a management concept for research associations, these characteristics must be considered. To ensure this, the project follows a human-centred approach, which considers top-down, as well as bottom-up perspectives. This paper presents the applied mixed-method approach in the scientific issue described above. In the frame of the Cluster of Excellence “Integrative Production Technology for High-Wage Countries” research results based on quantitative, as well as qualitative studies, were presented as an application example. This paper provides a new perspective on the innovation and diversity context. Against the background of complex research organisations, the development approach of a management concept is particularly interesting.
Reinforced concrete frames with masonry infill walls are popular form of construction all over the world as well in seismic regions. While severe earthquakes can cause high level of damage of both reinforced concrete and masonry infills, earthquakes of lower to medium intensity some-times can cause significant level of damage of masonry infill walls. Especially important is the level of damage of face loaded infill masonry walls (out-of-plane direction) as out-of-plane load cannot only bring high level of damage to the wall, it can also be life-threating for the people near the wall. The response in out-of-plane direction directly depends on the prior in-plane damage, as previous investigation shown that it decreases resistance capacity of the in-fills. Behaviour of infill masonry walls with and without prior in-plane load is investigated in the experimental campaign and the results are presented in this paper. These results are later compared with analytical approaches for the out-of-plane resistance from the literature. Conclusions based on the experimental campaign on the influence of prior in-plane damage on the out-of-plane response of infill walls are compared with the conclusions from other authors who investigated the same problematic.