TY - CONF A1 - Thöns, Sebastian A1 - Faber, M.H. A1 - Rücker, Werner ED - Faber, M.H. ED - Köhler, J. ED - Nishijima, K. T1 - On the utilization of monitoring data in an ultimate limit state reliability analysis N2 - This paper describes a structural reliability analysis utilizing monitoring data in the ultimate limit state with consideration of the uncertainties of the monitoring procedure. For this purpose the uncertainties of the monitoring data are modeled utilizing a new framework for the determination of measurement uncertainties. The approach is based on a process equation and Statistical models of observations for the derivation of a posterior measurement uncertainty by Bayesian updating. This facilitates the quantification of a measurement uncertainty using all available data of the measurement process. For the reliability analysis in the ultimate limit state, monitoring data can be utilized as a loading model Information and as proof loading, i.e. resistance model Information. Both approaches are discussed with generic examples and it is shown that the modeling of monitoring data in a reliability analysis can result in a reduction of uncertainties and as a consequence in the reduction of the probability of failure. Furthermore, the proof loading concept is developed further to account for the uncertain characteristic of proof loading due to the measurement uncertainties which is consistent with the framework for the determination of measurement uncertainties. These approaches and findings can be utilized for the assessment of structures for life cycle extension and the design of monitoring Systems. T2 - ICASP 11 - 11th International conference on applications of statistics and probability in civil engineering CY - Zurich, Switzerland DA - 01.08.2011 PY - 2011 SN - 978-0-415-66986-3 SP - 1762 EP - 1769 PB - Taylor & Francis CY - London AN - OPUS4-24292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohrmann, Rolf A1 - Thöns, Sebastian A1 - Rücker, Werner A1 - Bicker, S. A1 - Said, Samir A1 - Schmid, Wolfgang T1 - Structural investigations and monitoring results on a prototype of offshore wind turbines of multibrid M5000 series N2 - The concept and technical details of the implementation of the developed integrated monitoring system within the IMO-WIND project are presented. The tasks of the components of the system and its requirements are described. Selected results from the continuous monitoring during operation of the plant M5000_2 regarding the task design verification and dynamic structural analysis are given. T2 - DEWEK 2010 - 10th German wind energy conference CY - Bremen, Germany DA - 2010-11-17 KW - Integrated monitoring system KW - Offshore wind turbines KW - Design verification KW - Structural assessment KW - Limit values KW - Load transfer KW - Data management KW - Dynamic analysis KW - Rotor blades KW - Embedded sensors PY - 2011 IS - S03 SP - 1 EP - 5 PB - DEWI GmbH AN - OPUS4-23712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohrmann, Rolf A1 - Rücker, Werner A1 - Thöns, Sebastian T1 - Integrated Monitoring Systems for Offshore Wind Turbines T2 - 6th International Workshop on Structural Health Monitoring CY - Stanford, USA DA - 2007-09-11 KW - Integrated Monitoring System KW - Damage Identification KW - Load Monitoring KW - Wind turbines PY - 2007 SP - 1 EP - 8 AN - OPUS4-16280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thöns, Sebastian A1 - Döhler, M. ED - del Grosso, A. E. ED - Basso, P. T1 - Structural reliability updating with stochastic subspace damage detection information N2 - Damage detection algorithms as a part of Structural Health Monitoring (SHM) are widely applied in research and industry and have shown their capabilities to efficiently detect structural damages. These algorithms usually compare a model front a safe reference state of a structure to Vibration data from a possibly damaged state. For such a comparison, special properties of real Vibration data introduce uncertainties, such as low signal-to-noise ratios, non-stationary or nonwhite ambient excitation, non-linear behavior and many more. Recently, Statistical damage detection algorithms based on stochastic subspace Identification have been proposed that take into account the uncertainties in the data. Building upon the uncertainty modeling, the next step in the view of the authors is to utilize damage detection algorithm information in the context of the structural reliability theory. Therefore, this paper introduces an approach for the updating of the structural reliability with damage detection algorithm information. Two steps are described namely the determination of a probability of detection (PoD) distribution function for damage detection algorithms accounting for the relevant uncertainties and the concept of Bayesian updating of the structural reliability. The introduced approaches are applied in generic examples. In this way the potential of the utilization of damage detection system information for more reliable structural systems are demonstrated. T2 - EACS 2012 - Smart Structures - 5th European Conference on Structural Control CY - Genoa, Italy DA - 18.06.2012 KW - Stochastic subspace KW - Structural reliability KW - Bayesian updating KW - Probability of detection PY - 2012 SN - 978-88-95023-13-7 IS - Paper #008 SP - 1 EP - 12 PB - Erredi Grafiche Editoriali CY - Genoa AN - OPUS4-26181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Frederik A1 - Löhnert, Andrea A1 - Knaust, Christian A1 - Thöns, Sebastian T1 - Numerical quantification of fire smoke toxicity in tunnels N2 - Vehicle fires in tunnels can have catastrophic consequences for the road users, the property and traffic inffastructure. To support an evacuation planning, this study simulates the fire smoke toxicity and the smoke layer of a vehicle fire in a full-size test tunnel. The three dimensional prediction of the fire smoke toxicity in the test tunnel is realized by implementing the Fractional Effective Dose and the Fractional Summation concept in a CFD environment. The developed model facilitates to calculate fire scenarios for various types of tunnels and to quantify the hazard e.g. during an evacuation scenario. T2 - ISAVFT 15 - 15th International symposium on aerodynamics, ventilation and fire in tunnels CY - Barcelona, Spain DA - 18.09.2013 KW - Toxicity KW - Fire KW - Smoke KW - Tunnel KW - FED KW - Fractional effective dose PY - 2013 SN - 978-1-85598-137-9 SP - 203 EP - 215 AN - OPUS4-29719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Berchtold, Florian A1 - Thöns, Sebastian A1 - Knaust, Christian A1 - Rogge, Andreas T1 - Review of road tunnel risk assessment - common aspects? N2 - Safety measures like tunnel emergency Ventilation Systems cause high financial costs. Hence, safety measures have to be chosen with the focus on the expected reduction of the consequences like fatalities or damage on structures and in conjunction with the investments. Since 2004, the European directive EU 2004/54/EC proposes therefore the application of risk assessments. Because the EU directive provides only few legal requirements on risk assessments, the methodologies developed on this basis have large differences. After one decade of intensive research, the comparative study now highlights common aspects and differences of several methodologies. T2 - 6th International symposium on tunnel safety and security CY - Marseille, France DA - 12.03.2014 KW - Tunnel KW - System KW - Risk assessment KW - Fire KW - Safety KW - Comparative study PY - 2014 SP - 669 EP - 670 AN - OPUS4-31256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Thöns, Sebastian A1 - Said, Samir A1 - Schmid, Wolfgang ED - Zingoni, A. T1 - SHM strategies, application and measurements on tripod offshore wind energy converters within the German offshore park Alpha Ventus N2 - Prototypes of wind turbines of the megawatt dass are to be built and tested until 2008 within a German offshore wind energy test field in the North Sea (ALPHA VENTUS). To ensure a high operational reliability of offshore wind turbines with economically acceptable repair and maintenance efforts, comprehensive diagnosis and supervision concepts are required. Automatic monitoring Systems will be an essential part of such concepts. Because of the fact, that during Operation there will be static and dynamic interaction between the components ‘structure’, ‘machinery’ and ‘blades’ it is necessary to develop the monitoring techniques in an overall concept. These monitoring Systems are supposed to be applied for the design and testing as well as for the Operation and maintenance phases. In the paper the developed approaches for the measurement of actions and the condition monitoring of all components of an offshore wind energy plant will be shown. T2 - Research and applications in structural engineering, mechanics and computation - 5th International conference on structural engineering, mechanics and computation CY - Cape Town, South Africa DA - 02.09.2013 PY - 2013 SN - 978-1-138-00061-2 SN - 978-1-315-85078-8 SP - 977 EP - 982 PB - CRC Press AN - OPUS4-29104 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohrmann, Rolf A1 - Rücker, Werner A1 - Thöns, Sebastian A1 - Said, Samir T1 - Design and operation of integrated monitoring systems for offshore wind turbines N2 - To ensure a high operational reliability of future generations of offshore wind conversion systems (OWEC) with economically acceptable repair and maintenance efforts, comprehensive diagnosis and supervision concepts are required. Automatic monitoring systems will be an essential part of such concepts. Because of the fact, that during operation there will be static and dynamic interaction between the components 'structure', 'machinery' and 'blades' it is necessary to develop the monitoring techniques in an overall concept. These monitoring systems are supposed to be applied for the design and testing as well as for the operation and maintenance phases. The used methods are focused on the design requirements for the structure, which are stated in the respective standards and certification guidelines. For the validation of the design, methods are specified which would be also applicable for SHM in the operating condition, e.g. for the evaluation of the structural conditon possibly after the occurrence of damages or changes. The further task consists in the realization of condition monitoring for all components, aiming at early damage detection and the observation of the damage development and its evaluation. Here the task consists of determining with assessment procedures the optimum time for maintenance actions to be carried out. T2 - DEWEK 2008 - 9th German wind energy conference CY - Bremen, Germany DA - 2008-11-26 KW - Integrated monitoring system KW - Offshore wind turbines KW - Assessment KW - Damage identification KW - Load monitoring PY - 2008 SP - 1 EP - 4(?) AN - OPUS4-19872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald A1 - Thöns, Sebastian A1 - Rücker, Werner A1 - Straub, D. ED - Deodatis, G. ED - Ellingwood, B.R. ED - Frangopol, D.M. T1 - Effect of different inspections strategies on the reliability of Daniels systems subjected to fatigue N2 - Inspections are an efficient means of enhancing the reliability of redundant structural Systems subjected to fatigue. To investigate the effect of such inspections, we represent the deterioration state of a Daniels System by means of a probabilistic fatigue crack growth model of all elements, which considers stochastic dependence among element fatigue behavior. We include inspection results in the calculation of the System collapse probability through Bayesian updating of the System deterioration state. Based on this approach, we calculate the collapse probability of a deteriorating Daniels System conditional on different inspection strategies in terms of inspection coverage and inspection times. The acceptability of an inspection strategy is verified by comparing the calculated collapse probabilities with maximum acceptable System failure probabilities. This study is a Step towards identifying optimal inspection strategies for redundant structural Systems subjected to fatigue. T2 - 11th International conference on structural safety and reliability - Safety, reliability, risk and life-cycle performance of structures and infrastructures CY - New York, USA DA - 16.06.2013 PY - 2013 SN - 978-1-138-00086-5 SN - 978-1-315-88488-2 SP - 1 EP - 8 PB - CRC Press CY - Leiden, The Netherlands AN - OPUS4-28984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Faber, M.H. A1 - Thöns, Sebastian ED - Miraglia, S. ED - Vrouwenvelder, A.C.W.M. ED - Steenbergen, R.D.J.M. ED - Van Gelder, P.H.A.J.M. T1 - On the value of structural health monitoring N2 - Health monitoring has, over the last 2-3 decades, become a topic of significant interest within the structural engineering research community, but also in the broader areas of civil and mechanical engineering. Whereas the merits of Structural Health Monitoring (SHM) are generally appreciated in qualitative terms there has, as of yet, not been reported much fundamental research on the quantification of the benefit of SHM. The present paper addresses the quantification of SHM with basis in the Bayesian pre-posterior decision analysis. The starting points are historical and recent developments in the fields of SHM and the quantification of value of information as well as the identification of typical situations in structural engineering in which SHM has the potential to provide value beyond its costs. Subsequently, the theoretical framework which allows for the quantification of the value of information collected through SHM Systems is developed and elaborated. It is shown how the value of information can be quantified to support the assessment and optimization of decisions on whether and how to implement SHM. To illustrate the use of the developed theoretical framework for evaiuating the benefit of SHM an example is provided. The example addresses the life-cycle benefit maximization for offshore jacket structures subject to fatigue crack growth utilizing monitoring of near field fatigue stresses as a means of optimizing risk based inspection and maintenance strategies. T2 - 22nd ESREL conference - Safety, reliability and risk analysis: Beyond the horizon CY - Amsterdam, The Netherlands DA - 29.09.2013 PY - 2014 SN - 978-1-138-00123-7 SP - 2535 EP - 2544 PB - Taylor & Francis AN - OPUS4-29894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -