@article{ChatzitakisSafarovOpferkuchetal., author = {Chatzitakis, Paris and Safarov, Javid and Opferkuch, Frank and Dawoud, Belal}, title = {Experimental investigation of an absorption heat pump with organic working pairs}, series = {Applied Thermal Engineering}, volume = {163}, journal = {Applied Thermal Engineering}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2019.114311}, abstract = {As part of a systematic approach towards the search for alternative absorption heat pump (AHP) working pairs that could potentially provide comparable performance to conventional ones, a previous work performed a detailed theoretical cycle analysis and simulation that revealed concrete correlations between key working fluid thermophysical properties and AHP performance indicators. Following this work, targeted combinations of two organic refrigerants, 2,2,2-trifluoroethanol (TFE) and 2,2,3,3,3-pentafluoropropanol (5FP) and two organic absorbents, 1,3-dimethyl-2-imidazolidinone (DMI) and 2-pyrrolidone (PYR) were tested in a prototype 5 kW AHP, based on a highly compact plate heat exchanger design, which has been previously introduced. The purpose of this effort was to test the findings of the previous work with experimental measurements. The working pair combinations were also subjected to vapor liquid equilibrium (VLE) and viscosity measurements, in order to determine reliable activity coefficient and improve the accuracy of the simulations. The experimental performance data agree well with the COP simulations and show to be consistent with the conclusions derived from the previous theoretical work.}, language = {en} } @article{HansenHoeblerPurretal., author = {Hansen, B. and Hoebler, Michael and Purr, Stephan and Meinhardt, J. and Merklein, Marion}, title = {Basics for inline measurement of tribological conditions in series production of car body parts}, series = {IOP Conference Series: Materials Science and Engineering}, volume = {651}, journal = {IOP Conference Series: Materials Science and Engineering}, publisher = {IOP Publishing}, doi = {10.1088/1757-899x/651/1/012050}, abstract = {The quality of car body parts in series production is strongly dependent on the tribological behavior. Fluctuating material properties such as the sheet roughness and the amount of lubricant have an influence on the forming process. On the basis of large amounts of data it is possible to investigate the friction behavior in series production and to make process adjustments if required. Therefore, inline measurement systems have a great potential to detect the sheet roughness during the cutting process of blanks in the coil line. Furthermore, contactless systems are advantageous as they do not damage the surface. Nevertheless, the optical measuring is influenced by the lubricant layer on top of the surface. Therefore, the previously unknown impact of the lubricant on the measuring result is investigated. Within this study, stationary optical roughness measurements have been conducted using different amounts of lubricant on hot-dip galvanized EDT steel. The results demonstrate the influence of different amounts of lubricant on the sheet roughness measurement. Hence, it is possible to correct the inline measuring results and gain knowledge of fluctuating surface roughness. In addition, strip drawing test has been carried out to investigate the effect of fluctuating tribological conditions.}, language = {en} } @article{SavelevFetisovChashinetal., author = {Savelev, Dmitrii V. and Fetisov, Leonid Y. and Chashin, Dmitri V. and Shabin, P. A. and Vyunik, D. A. and Fedulov, Feodor and Kettl, Wolfgang and Shamonin (Chamonine), Mikhail}, title = {Method of Measuring Deformations of Magnetoactive Elastomers under the Action of Magnetic Fields}, series = {Russian Technological Journal}, volume = {7}, journal = {Russian Technological Journal}, number = {4}, doi = {10.32362/2500-316x-2019-7-4-81-91}, pages = {81 -- 91}, language = {ru} } @inproceedings{ParedesKeimNonnetal., author = {Paredes, Marcelo and Keim, Vincent and Nonn, Aida and Wierzbicki, Tomasz}, title = {Effect of plasticity parameter on the crack propagation in steel pipelines}, series = {Proceedings of the conference on Technology for future and ageing piplines, Ghent, Belgium}, booktitle = {Proceedings of the conference on Technology for future and ageing piplines, Ghent, Belgium}, language = {en} } @article{DiamantidisSykoraLenzi, author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav and Lenzi, Daniele}, title = {Optimising Monitoring: Standards, Reliability Basis and Application to Assessment of Roof Snow Load Risks}, series = {Structural Engineering International}, volume = {28}, journal = {Structural Engineering International}, number = {3}, publisher = {Taylor\&Francis}, doi = {10.1080/10168664.2018.1462131}, pages = {269 -- 279}, abstract = {This paper addresses the optimisation of monitoring and decision-making criteria regarding the future use of structures. The current state of practice in standards and reliability framework are initially summarised. A general methodology for obtaining cost-optimal decisions is then presented on the basis of limit state design, probabilistic reliability analysis and cost estimates. The implementation of the risk-based approach is illustrated in a case study dealing with the roof of a stadium located in northern Italy. As the roof fails to comply with the requirements of the Eurocodes, the installation of a permanent monitoring system is recommended to allow for a real-time reliability assessment. The results demonstrate the potential of monitoring systems and probabilistic reliability analysis for supporting decisions regarding safety measures such as snow removal or temporary closure of the stadium, as well as reflecting the need to implement the discussed procedures in future standards.}, language = {en} } @article{DiermeierSindersbergerKrenkeletal., author = {Diermeier, Andreas and Sindersberger, Dirk and Krenkel, Lars and Rosell, X. C. and Monkman, Gareth J.}, title = {Controllable Magnetoactive Polymer Conduit}, series = {The Open Mechanical Engineering Journal}, volume = {12}, journal = {The Open Mechanical Engineering Journal}, number = {1}, publisher = {Bentham}, pages = {192 -- 200}, abstract = {Objective: Magneto-active Polymers (MAP) are smart materials whose mechanical characteristics, such as elastic and shear moduli, may be controllable by means of an externally applied magnetic field. Methods: Various additives may be used to influence the characteristics of the polymer matrix whilst a suspension of soft and/or hard magnetic particles determine the magnetic properties of the composite. Both pre-cure and post-cure magnetization is possible. Results: A range of control strategies have been investigated for evaluation of the system using fluids of differing kinematic viscosity. Conclusion: Depending on the degree of magnetic field homogeneity, magneto-deformation and magnetostriction contribute to MAP actuation. This paper presents a novel application in the form of a peristaltic MAP tube system, applicable to flow control and pumping of hemorheological fluids in blood circulatory systems for biomedical research purposes.}, language = {en} } @article{Brueckl, author = {Br{\"u}ckl, Oliver}, title = {Pl{\"a}doyer f{\"u}r die wettbewerbliche Bereitstellung von Blindleistung}, series = {ew - Magazin f{\"u}r die Energiewirtschaft - Spezial: Digitalisierung}, volume = {117}, journal = {ew - Magazin f{\"u}r die Energiewirtschaft - Spezial: Digitalisierung}, number = {1}, publisher = {VDE Verlag}, organization = {VDE Verlag}, pages = {46 -- 48}, language = {de} } @inproceedings{HaslbeckBrueckl, author = {Haslbeck, Matthias and Br{\"u}ckl, Oliver}, title = {Netzplanungsprozess zur dezentralen Nutzung von Blindleistungsquellen in Verteilungsnetzen}, series = {Tagungsband der Fachtagung "Zuk{\"u}nftige Stromnetze f{\"u}r erneuerbare Energien" am 30./31. Januar 2018 in Berlin}, booktitle = {Tagungsband der Fachtagung "Zuk{\"u}nftige Stromnetze f{\"u}r erneuerbare Energien" am 30./31. Januar 2018 in Berlin}, abstract = {Das vom BMWi gef{\"o}rderte Forschungsprojekt SyNErgie (03/2015 bis 05/2018) besch{\"a}ftigt sich mit der Weiterentwicklung von Netzplanungsprozessen [1]. Im Fokus steht dabei die Modellierung von Blindleistungsfl{\"u}ssen und die dezentrale Nutzung von Blindleistungsquellen (z. B. Wechselrichter, Ladedrosseln, Kondensatoren) in Mittelspannungsnetzen, {\"u}ber welche der Blindleistungshaushalt letztendlich beeinflusst werden soll. Diese Ver{\"o}ffentlichung konzentriert sich auf die konzipierte Erweiterung des Netzplanungsprozesses zur Einbindung von Blindleistungsquellen im Verteilungsnetz in ein Blindleistungsmanagement. Deren einzelne Phasen werden erl{\"a}utert und anschließend die Netz-Sensitivit{\"a}ts- und -Restriktionsanalyse anhand eines realen Mittelspannungsnetzes demonstriert. Abschließend werden m{\"o}gliche Abschw{\"a}chungs- und Verst{\"a}rkungseffekte im Hinblick auf einen Blindleistungsabruf {\"u}ber mehrere Spannungsebenen hinweg diskutiert.}, language = {de} } @inproceedings{KreuzerHaslbeckBrueckl, author = {Kreuzer, Reinhard and Haslbeck, Matthias and Br{\"u}ckl, Oliver}, title = {Modellierung von Mittelspannungsnetzen zur verbesserten Nachbildung von Wirk- und Blindleistungsfl{\"u}ssen}, series = {Tagungsband der Fachtagung "Zuk{\"u}nftige Stromnetze f{\"u}r erneuerbare Energien" am 30./31. Januar 2018 in Berlin}, booktitle = {Tagungsband der Fachtagung "Zuk{\"u}nftige Stromnetze f{\"u}r erneuerbare Energien" am 30./31. Januar 2018 in Berlin}, abstract = {Das vom BMWi gef{\"o}rderte Forschungsprojekt SyNErgie (03/2015 bis 05/2018) besch{\"a}ftigt sich mit der Weiterentwicklung von Netzplanungsprozessen [1]. Im Fokus steht dabei die Modellierung von Blindleistungsfl{\"u}ssen und die dezentrale Nutzung von Blindleistungsquellen (z. B. Wechselrichter, Ladedrosseln, Kondensatoren) in Mittelspannungsnetzen, {\"u}ber welche der Blindleistungshaushalt letztendlich beeinflusst werden soll. Im Rahmen dieses Beitrags wird anhand eines realen Mittelspannungsnetzes (MS-Netz) gezeigt, welche Modellierungsschritte zur Erstellung eines m{\"o}glichst realit{\"a}tsnahen Simulationsabbilds n{\"o}tig sind. Dies ist notwendig, um der Verteilnetzplanung eine robuste Planungsgrundlage f{\"u}r die Ableitung von Entscheidungen im Rahmen eines Blindleistungsmanagements zur Verf{\"u}gung zu stellen.}, language = {de} } @inproceedings{BerlingHaslbeckBrueckl, author = {Berling, Andreas and Haslbeck, Matthias and Br{\"u}ckl, Oliver}, title = {Interpretation und Relevanz verschiedener Blindleistungsarten f{\"u}r die Modellierung von Niederspannungsnetzen in der Netzplanung}, series = {Tagungsband der Fachtagung "Zuk{\"u}nftige Stromnetze f{\"u}r erneuerbare Energien" am 30./31. Januar 2018 in Berlin}, booktitle = {Tagungsband der Fachtagung "Zuk{\"u}nftige Stromnetze f{\"u}r erneuerbare Energien" am 30./31. Januar 2018 in Berlin}, language = {de} } @article{KoderSchwanzerZacherletal., author = {Koder, Alexander and Schwanzer, Peter and Zacherl, Florian and Rabl, Hans-Peter and Mayer, Wolfgang and Gruber, Georg and Dotzer, Thomas}, title = {Combustion and emission characteristics of a 2.2L common-rail diesel engine fueled with jatropha oil, soybean oil, and diesel fuel at various EGR-rates}, series = {Fuel}, volume = {228}, journal = {Fuel}, number = {September}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2018.04.147}, pages = {23 -- 29}, abstract = {To investigate the combustion and emission behavior of straight vegetable oils (SVO), jatropha oil, soybean oil, and diesel fuel were tested. For this research, a 2.2L common-rail engine with a two-stage turbocharging concept was equipped with a cylinder pressure indication system, an exhaust-gas analyzer, an AVL Micro Soot sensor and a Scanning Mobility Particle Sizer 3936 (SMPS) device to detect the particle-size-distribution (PSD). At a low and mid-load engine-operating point (EOP), the thermodynamic and emissions were investigated under various exhaust gas recirculation (EGR) rates with respect to the PSD. Moreover, the injection behavior of the three test fuels was analyzed separately using an injection rate analyzer. This procedure facilitates the thermodynamic investigations of the engine process and allows the calculation of the hydraulic delay (HD) as well as the ignition delay (ID). The ID of the SVO fuels compared to diesel fuel was found to be lower at all engine-operating modes, while jatropha oil always showed the shortest ID. In the particulate-nitrogen oxide (NOX) trade-off, the SVO fuels showed higher particulate matter (PM) emissions at the low-load EOP, whereas the PM emissions of diesel fuel overtop the SVO fuels at a higher engine load. With increased EGR-rates, a rise in the particle size was observed for all fuels. At the low-load EOP, the SVO fuels showed larger particles for high EGR-rates. This effect also changed by increasing the engine-load to the mid-load EOP, wherein the particle size of the diesel fuel emissions is higher by applying elevated EGR-rates.}, language = {en} } @incollection{StadlerSterner, author = {Stadler, Ingo and Sterner, Michael}, title = {Urban Energy Storage and Sector Coupling}, series = {Urban Energy Transition}, booktitle = {Urban Energy Transition}, editor = {Droege, Peter}, edition = {2. ed.}, publisher = {Elsevier}, isbn = {978-0-08-102074-6}, doi = {10.1016/B978-0-08-102074-6.00026-7}, pages = {225 -- 244}, abstract = {Global warming, greenhouse gas emissions, and the general transition toward renewable energy resources are mentioned many times within this book, and will not be repeated again here. Countries that are transitioning to use of more renewable energy sources are mainly using wind and solar power—except for a few countries that, due to their prerequisites, will mainly use hydro power and/or bioenergy. The transmission process in terms of energy generation so far is mainly happening in rural areas—not in urban centers. Most technologies do not really play an important role in urban areas, and are mainly focused on the application of solar energy. Solar energy is widely applied more in rural areas, although investigations show that its application in urban areas already fits well into the existing grid infrastructure. Whereas rural areas are more prone to grid integration problems, the energy infrastructure in urban centers is already well prepared for renewables integration. In fostering tight bundles of potentially linked energy generation, distribution, networking, and use across power and thermal systems in stationary and mobile modes, urban centers become particularly critical in the energy transition processes as energy systems are becoming completely based on renewable sources without a nuclear or fossil-based backbone. This chapter discusses the almost unlimited energy storage possibilities. It will show their enormous capabilities, but also their significant differences in many physical and economical parameters. Next, the authors discuss the necessity of combining and coupling the different energy sectors for electricity, heat, cold, gas, and transport. Finally, the authors present the conclusion that only when coupling the energy sectors and using cheap and efficient energy storage options from one energy sector to solve challenges within another energy sector will the energy transition process be managed in an efficient way.}, language = {en} } @article{SykoraMarkovaDiamantidis, author = {S{\´y}kora, Miroslav and Markova, Jana and Diamantidis, Dimitris}, title = {Bayesian network application for the risk assessment of existing energy production units}, series = {Reliability Engineering \& System Safety}, volume = {169}, journal = {Reliability Engineering \& System Safety}, number = {January}, publisher = {Elsevier}, doi = {10.1016/j.ress.2017.09.006}, pages = {312 -- 320}, abstract = {The assessment of existing infrastructures in the energy sector is of great economic significance worldwide. Fossil power stations are reaching their design service life and rational decisions concerning extensions of service life, maintenance and replacements of devices should be based on updated information of the actual conditions of the energy devices and their components, and on cost-benefit analysis using risk analysis and probabilistic optimisation procedures. The contribution provides an integrated framework for probabilistic reliability and risk assessment of existing energy production units considering availability and human safety criteria. An extensive case study focused on risks of an energy production unit in a fossil power station is provided to support practical applications. A Bayesian network is thereby implemented to assess the risks of the selected production unit. Special emphasis is given to the input data consisting of failure rates obtained from recorded data and expert judgements. The influence of uncertainties in the considered performance indicators on the availability of the unit is analysed. It is shown that a reasonably simplified framework can provide a valuable assessment of the influence of individual devices and their components on availability and societal risk, identifying thus the major risk contributors. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{WeberHaug, author = {Weber, Karsten and Haug, Sonja}, title = {Ist automatisiertes Fahren nachhaltig?}, series = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, volume = {27}, journal = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, number = {2}, publisher = {Karlsruhe Institute of Technology (KIT)}, doi = {10.14512/tatup.27.2.16}, pages = {16 -- 22}, abstract = {Automatisiertes Fahren st{\"o}ßt derzeit noch auf große Skepsis. Eine disruptive Strategie bei der Einf{\"u}hrung (voll-)automatisierten Fahrens k{\"o}nnte daher auf fehlende Akzeptanz treffen. Um dem zu entgehen, laufen evolution{\"a}re Strategien darauf hinaus, durch die Entwicklung adaptiver Fahrassistenzsysteme Vertrautheit, Vertrauen und damit Akzeptanz bei den prospektiven NutzerInnen zu schaffen. Erste Ergebnisse einer Pilotstudie lassen jedoch Zweifel an der Nachhaltigkeit dieser Strategie aufkommen.}, language = {de} } @inproceedings{KeimNonnLenzetal., author = {Keim, Vincent and Nonn, Aida and Lenz, D. and Brinnel, Viktoria and M{\"u}nstermann, Sebastian}, title = {Simulation of the ductile fracture behaviour of high toughness pipeline steels using combined damage models}, series = {Proceedings of the conference on Technology for future and ageing piplines, Ghent, Belgium}, booktitle = {Proceedings of the conference on Technology for future and ageing piplines, Ghent, Belgium}, language = {en} } @article{LeeSchubertOoietal., author = {Lee, Wai-Kong and Schubert, Martin J. W. and Ooi, Boon Yaik and Ho, Stanley Jian-Qin}, title = {Multi-source energy harvesting and storage for floating wireless sensor network nodes with Long Range Communication Capability}, series = {IEEE Transactions on Industry Applications}, volume = {54}, journal = {IEEE Transactions on Industry Applications}, number = {3}, publisher = {IEEE}, doi = {10.1109/TIA.2018.2799}, pages = {2606 -- 2615}, abstract = {Wireless sensor networks are widely used for environmental monitoring in remote areas. They are mainly composed of wireless sensor nodes, usually powered by batteries with limited capacity, but are expected to communicate in long range and operate for extended time periods. To overcome these limitations, many energy harvesting techniques are proposed to power wireless nodes for prolonged operation, whereas multihop techniques are utilized to extend the communication range. In this paper, a novel floating device with multisource energy harvesting technology that can be used as a wireless sensor node is proposed. The long range communication between wireless sensor nodes and a gateway is established through LoRa technology. In addition to conventional solar panels, an energy harvesting technique based on thermoelectric generators exploiting thermal differences created between water surface and materials exposed to sunlight is proposed. Energy generated from photovoltaic and thermoelectric generators is combined to power the wireless sensor node. This floating device consumes 6.6216 Wh per day when used as a wireless sensor node for the collection and transmission of environmental data. The sensor node can operate on a water surface for at least 9.6 days when it is not exposed to sunlight. During a sunny day, the floating device can harvest 8.375 Wh from solar panels and 0.425 Wh from thermoelectric generation. In other words, the floating device harvests sufficient energy to be self-sustaining during sunny days.}, language = {en} } @inproceedings{WeberHaug, author = {Weber, Karsten and Haug, Sonja}, title = {Automatisiertes Fahren: Evolution{\"a}re Weiterentwicklung statt Disruption}, series = {Vierte Jahreskonferenz des Netzwerks INDIGO zum Thema "Mobilit{\"a}t", 23.11.2018, , TH Deggendorf}, booktitle = {Vierte Jahreskonferenz des Netzwerks INDIGO zum Thema "Mobilit{\"a}t", 23.11.2018, , TH Deggendorf}, language = {de} } @inproceedings{NonnParedesKeimetal., author = {Nonn, Aida and Paredes, Marcelo and Keim, Vincent and Wierzbicki, Tomasz}, title = {Comparison of Fracture Models to Quantify the Effects of Material Plasticity on the Ductile Fracture Propagation in Pipelines}, series = {Proceedings of the 2018 12th International Pipeline Conference, Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 24-28, 2018, Calgary, Alberta, Canada}, booktitle = {Proceedings of the 2018 12th International Pipeline Conference, Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 24-28, 2018, Calgary, Alberta, Canada}, doi = {10.1115/IPC2018-78366}, abstract = {Various numerical approaches have been developed in the last years aimed to simulate the ductile fracture propagation in pipelines transporting CO2 or natural gas. However, a reliable quantification of the influence of material plasticity on the fracture resistance is still missing. Therefore, more accurate description of the material plasticity on the ductile fracture propagation is required based on a suitable numerical methodology. In this study, different plasticity and fracture models are compared regarding the ductile fracture propagation in X100 pipeline steel with the objective to quantify the influence of plasticity parameters on the fracture resistance. The plastic behavior of the investigated material is considered by the quadratic yield surface in conjunction with a non-associated quadratic plastic flow potential. The strain hardening can be appropriately described by the mixed Swift-Voce law. The simulations of ductile fracture are conducted by an uncoupled, modified Mohr-Coulomb (MMC) and the micromechanically based Gurson-Tvergaard-Needleman (GTN) models. In contract to the original GTN model, the MMC model is capable of describing ductile failure over wide range of stress states. Thus, ductile fracture resistance can be estimated for various load and fracture scenarios. Both models are used for the simulation of fracture propagation in DWTT and 3D pressurized pipe sections. The results from the present work can serve as a basis for establishing the correlation between plasticity parameters and ductile fracture propagation.}, language = {en} } @article{SykoraHolickyJungetal., author = {S{\´y}kora, Miroslav and Holicky, Milan and Jung, Karel and Diamantidis, Dimitris}, title = {Human safety criteria for risk-based structural design}, series = {International Journal of Safety and Security Engineering}, volume = {8}, journal = {International Journal of Safety and Security Engineering}, number = {2}, publisher = {WIT Press}, doi = {10.2495/SAFE-V8-N2-287-298}, pages = {287 -- 298}, abstract = {Risk and reliability criteria are well established in many industrial sectors such as the offshore, chemi- cal or nuclear industries. Comparative risk thresholds have been specified to allow a responsible organization or regulator to identify activities, which impose an acceptable level of risk concerning the participating individuals, or society as a whole. The scope of this contribution is to present target reliability criteria based on acceptable human safety levels. Application of theoretical principles is illustrated by examples of railway engineering structures. Initially it is shown how civil engineering structures for which human safety criteria play a role are classified according to Eurocodes. Examples include bridges, tunnels or station buildings. The general concepts for risk acceptance are then briefly reviewed, particularly in their relation to the target reliability criteria. The distinction between the two types of criteria is made: group risk and the acceptance criterion based on the Life Quality Index LQI approach introduced by ISO 2394:2015. The differences between the criteria for new and existing structures are discussed. The application is illustrated by an example of a bridge crossing an important railway line. It appears that while benefits and costs of a private stakeholder or public authority are reflected by economic optimisation, the society should define the limits for human safety to achieve uniform risks for various daily-life activities and across different industrial sectors. Keywords: group risk, human safety, individual risk, Life Quality Index, railway, risk acceptance, structure, target reliability}, language = {en} } @inproceedings{DiamantidisSykoraBertacca, author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav and Bertacca, Elena}, title = {Obsolescence Rate: Framework, Analysis and Influence on Risk Acceptance Criteria}, series = {6th International Symposium on Life-Cycle Civil Engineering (IALCCE), Ghent, Belgium}, booktitle = {6th International Symposium on Life-Cycle Civil Engineering (IALCCE), Ghent, Belgium}, abstract = {Buildings are major long lasting assets of the society and business enterprises and form a significant part of infrastructure management. They require continual maintenance and in many cases they can become inap-propriate for their original purpose due to obsolescence and are demolished. The present contribution ex-plores the obsolescence of buildings and in particular the definitions of obsolescence, the related influenc-ing factors and the associated uncertainties. Thereby definitions of the obsolescence rate based on the physi-cal and useful (service) life are clarified. The experienced useful life of buildings in Finland, Germany and North America is statistically analysed, utilizing available databases, and comparisons with the design (minimum) working life specified in standards are made. The probability of not exceeding the required min-imum service life is evaluated and discussed. Whereas many factors affecting the obsolescence rate are be-yond the control of civil engineers, particular attention needs to be paid to cases where the service life of the structure is determined by physical aspects related to deterioration. These cases are identified and recom-mendations to improve structural design are offered. The service life and the related renewal rate is influ-encing the risk acceptance criteria as given in ISO 2394. Such criteria are derived on the basis of economic optimization and the LQI marginal safety costs principle. A statistical model for the renewal rate is obtained and its influence on the target reliability is investigated for a representative failure limit state. The influence of the obsolescence rate is quantified and critically disputed.}, language = {en} }