TY - JOUR A1 - Auersch, Lutz T1 - Mitigation of railway induced vibration at the track, in the transmission path through the soil and at the building N2 - This contribution presents some principles and some examples of the mitigation of railway-induced ground vibrations. The principles are different for the mitigation measures at the track, in the soil or at the building. Force transfer functions of isolated and un-isolated track-soil systems, reflected and transmitted wave amplitudes at walls and trenches in the soil, and the transfer of the (free-field) vibration amplitudes to the foundation amplitudes of the building are analysed. The mitigation effect can be calculated by exact or simplified formulas. Some examples with 3D (finite-element boundary-element), 2D (beam-on-support), and 1D track models, 2D and 1D soil models, detailed 3D building models and finite or infinite 1D wall-floor models are investigated to find out if simple models can be used for a satisfactory prediction of the mitigation effect. The 1D track examples show that the force transfer of the track without vehicle can be exactly calculated, whereas the total force transfer can be calculated approximately if appropriate wheelset masses per track length are used for the isolated and the un-isolated track. The mitigation effect of a filled trench is calculated by a 2D finite element model and the results compare with simple transmission formula if the stiffness per area rather than the wave impedances are used for the infill material. The base isolation of a building is analysed by a detailed 3D model and the results are similar to the analytic results of a single wall with floors on the soil. Other reduction measures as different floor and column dimensions are usually less effective so that the clearly best mitigation solution at a building is a partly or a complete base isolation. T2 - X INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS (EURODYN 2017) KW - Mitigation KW - Soil-building interaction KW - Base isolation KW - Ground vibration PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-420869 DO - https://doi.org/10.1016/j.proeng.2017.09.192 SN - 1877-7058 VL - 199 SP - 2312 EP - 2317 PB - Elsevier CY - London AN - OPUS4-42086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Steinfurth, Henrik A1 - Augustin, Sven A1 - Mecke, R. A1 - Schiller, M. A1 - Kernchen, A. A1 - Kalisch, U. A1 - Meinhardt, J. A1 - Hennen, C. A1 - Groll, E. T. A1 - Arnold, T. T1 - Characterisation of historic façades using active thermography with solar heating and optical methods N2 - Active thermography is well suited for the detection of delaminations and cracks in façade elements like plaster and tiles. Not only artificial heating but also solar heating can be used if the adjustment of the façade and the weather conditions are suitable. Optical methods like laser scanners, photogrammetric methods and crack tracking sensors are providing geometrical 3D data which can be used for a 3D mapping of thermograms and for providing data with higher geometrical resolution. Thus, by the combination and fusion of these data, a comprehensive mapping and monitoring of damages of façade systems is possible. T2 - 19th World Conference on Non-destructive Testing (WCNDT) CY - München, Germany DA - 13.06.2016 KW - Non-destructive testing KW - Active thermography KW - Solar heating KW - Historic facades KW - Optical methods PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366833 SN - 978-3-940283-78-8 VL - BB 158 SP - Mo.2.C.2., 1 EP - 8 PB - DGZfP CY - Berlin AN - OPUS4-36683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schlick-Hasper, Eva A1 - Seidler, Oliver A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Helium leak testing of dangerous goods packagings N2 - The International Dangerous Goods Regulations prescribe the immersion under water method (“bubble test”) as standard method for the leakproofness test of dangerous goods packagings. But this test procedure acts as a test method for leak localisation, not for quantitative leakage rates measurement. Additionally, the sensitivity in detecting leaks of small diameters is restricted, depending on the test liquid and the test pressure. The bubble test is not suitable for a comparison with quantitative limit leakage rates based on realistic transport conditions. This is especially important when estimating the risk of the formation of an explosive atmosphere during the intercontinental carriage of dangerous goods packagings in freight containers. To compare measured leakage rates with limit leakage rates, a quantitative leak testing procedure is required. Therefore a new approach for dangerous goods packagings is implemented: The pressure technique by accumulation using Helium as a tracer gas. This work presents the test equipment necessary for the quantitative measurement of Helium leakage rates through closures of different kinds of dangerous goods packagings. The essential steps to achieve good repeatable results are: A controlled Helium filling process to reach a defined test pressure in the test sample, a sufficient homogenisation of the Helium-air-mixture inside the test sample and the ensuring of a constant pressure level of the test sample during the test. The Helium loss rate of the accumulation chamber has to be measured separately to receive a correction factor for the measured leakage rates. Different constructional measures are introduced to prevent a disturbing influence of the Helium leakage rate of the filling valves on the measurement results. Methods to estimate the disturbing effect of Helium permeation through permeable parts of the test sample are also presented. As a supporting method for the experimental investigations the Helium sniffer test can be applied. This practical application-oriented advice can enable other users to establish a pressure technique by accumulation for their own technical field. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Gefahrgutverpackungen KW - Dichtheit KW - Helium KW - Überdruckverfahren PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366358 SN - 978-3-940283-78-8 VL - 158 SP - p175, 1 EP - 10 AN - OPUS4-36635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fuggini, C. A1 - Zangani, D. A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Franitza, P. A1 - Gabino, L. A1 - Weigand, F. T1 - Innovative approach in the use of geotextiles for failures prevention in railway embankments N2 - Maintenance and renewal costs of a typical railway, track and substructure represents 50–60% of the total costs of such infrastructure over its entire service life. Innovations in track and substructure are therefore fundamental to achieve a significant impact on the overall cost reduction for the railways. Therefore new solutions for track improvements that are effective and that can minimize the interruption of traffic are needed. Moreover, failures of railway embankments happened recently in different regions of the world. Such events, such as the one happened in UK in February 2013 (http://www.bbc.co.uk/news/uk-england-south-yorkshire-21441070), are showing the importance of monitoring track and infrastructure coupled with the use of numerical models for the localization of the critical areas and the design of appropriate countermeasures. Indeed embankment failures, landslides and uneven settlements and similar events are becoming much more common than in the past due to climate changes, and this requires the infrastructure managers to look from a different perspective infrastructure maintenance issues. What was previously consider as “extreme” is now “common” and thus actions need to be taken to be ready when such events will happen. The aim is to mitigate their effects on the infrastructure and to minimize disruptions to train services and reduce maintenance costs to restore the normal service conditions. If this mental change happens, then the need for solutions and techniques for global asset monitoring and ground stabilization will probably increase. Among the others, geotextiles and geogrids for soil reinforcement used in combination with condition monitoring techniques have the potential for minimizing catastrophic events, whilst at the same time providing a good balance among costs and benefits (i.e. sustainability). The paper describe a case study where the use of multifunctional geotextiles, able to provide both strengthening and monitoring functions, has been tested along a railroad near the city of Chemnitz (Germany). The results are here reported to show the potential use and the innovative aspect of this solution. T2 - 6th Transport Research Arena (TRA) CY - Warsaw, Poland DA - 18.04.2016 KW - smart geotextile KW - failure prevention KW - railway embankment KW - fiber optic sensor KW - distributed sensor PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-379256 DO - https://doi.org/10.1016/j.trpro.2016.05.154 VL - 14 SP - 1875 EP - 1883 PB - Elsevier B.V. AN - OPUS4-37925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Said, Samir A1 - Müller, Roger T1 - Measurements on the vehicle-track interaction and the excitation of railway-induced ground vibration N2 - Two railway measurement campaigns have been performed in Germany and Switzerland which yield insight in the vehicle-track-soil interaction. The campaign in Germany has included simultaneous measurement of vehicle, track, and soil vibrations during train runs with 16, 25, 40, 63, 80, 100, 125, 140, 160 km/h, and impulse measurements of the passenger car, three track sections and the soil. Two ballast tracks, one on the soil surface and one on a concrete bridge, have been investigated as well as a slab track in a tunnel. Ten different sites in Switzerland have been measured for soil properties and train-induced ground vibrations, which allow to determine the excitation forces of the railway traffic. New axle-box measurements at some of the Swiss sites have been analysed to get further experimental evidence. All these measurements have been evaluated to characterize the excitation processes. Relations between vehicle vibration and ground vibration can be observed. The vehicle vibrations, namely the accelerations of the wheelsets, yield the dynamic forces due to the passage over the irregularities of the vehicle and the track. The ground vibrations are correlated to these dynamic forces to a certain extent. Some mid-frequency ground vibration amplitudes, however, are higher than expected from the dynamic excitation forces. The experimental observations can be explained by an irregular response to the passage of the static loads, that means the passage of the static loads over an irregular ballast or soil. This correct understanding of the excitation processes is important for the prediction as well as for the mitigation of railway induced ground vibrations. T2 - X INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS (EURODYN 2017) KW - Vehicle-track interaction KW - Ground vibration KW - Track vibration KW - Railway measurement campaign KW - Axle box measurements PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-420889 DO - https://doi.org/10.1016/j.proeng.2017.09.390 SN - 1877-7058 VL - 199 SP - 2615 EP - 2620 PB - Elsevier CY - London AN - OPUS4-42088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN T1 - Forschungsprogramm 2015 - 2017 N2 - Globalisierung und die beschleunigte technologische Entwicklung bringen heute für die Industrieländer Herausforderungen im Hinblick auf Wachstum, Beschäftigung und Strukturwandel mit sich, denen nur mit einer entsprechenden Innovationsdynamik und -dichte begegnet werden kann. Grundvoraussetzung hierfür ist eine leistungsfähige Forschung und Entwicklung ebenso wie Wissens- und Technologietransfer zur Umsetzung von Forschungsergebnissen in marktfähige Produkte und Dienstleistungen. Europa hat sich im Rahmen des Lissabon-Prozesses zum Ziel gesetzt, den Anteil der Forschungsausgaben am Bruttoinlandsprodukt auf 3 % zu steigern. Um die Forschungsinfrastruktur in der Bundesrepublik zu stärken und global wettbewerbsfähig zu bleiben, hat die Bundesregierung mit der Hightech-Strategie einen weiteren wichtigen Schritt zur Förderung des wissenschaftlich-technischen Fortschritts in Deutschland getan. Forschungsprogramme sind sowohl für Forschungseinrichtungen als auch für Mittelgeber ein wichtiges Instrument für die Darstellung und Steuerung ihrer Aktivitäten. Dies gilt auch für die Bundeseinrichtungen mit Forschungs- und Entwicklungsaufgaben, zu denen die Bundesanstalt für Materialforschung und -prüfung (BAM) zählt. Die BAM verfügt über einen klaren gesetzlichen Auftrag für die Sicherheit in Technik und Chemie. Ihre Forschung ist mit der Wahrnehmung öffentlicher Aufgaben verbunden. Das Forschungsprogramm zeigt Perspektiven im Bereich ihres Aufgabenfeldes sowie ihrer damit verbundenen Forschungsaktivitäten transparent und politisch nutzbar auf und dient darüber hinaus der Koordinierung der Ressortforschung. Das Forschungsprogramm der BAM wird alle zwei Jahre aktualisiert. Es gibt einen Überblick über die aktuellen und zukünftigen Forschungsthemen und die hierfür erforderlichen Rahmenbedingungen. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-421401 SP - 1 EP - 40 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-42140 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kapoor, M. A1 - Sørensen, J. D. A1 - Ghosh, S. A1 - Thöns, Sebastian T1 - Decision theoretic approach for identification of optimal proof load with sparse resistance information N2 - Proof load testing may be performed to confirm the reliability of the bridge for an existing classification or to prove the reliability for a higher classification. In this paper, a probabilistic decision analysis approach is applied to the scenario for the evaluation of target proof load in the situation where information on the bridge resistance model is lacking. In this case, the resistance model is established by proof loading and taking very basic prior knowledge into account. The decision scenario is modelled in the context of the proof load test planner who shall choose the required load level for assessment of a bridge. The choice of the load level depends on the risks due to the testing and the expected benefit gain from the test. Information acquired about the loading response from monitoring during the proof load testing is modelled by taking basis in the model uncertainty formulation. The optimal proof load level for classification of a single lane, simply supported bridge of 8m span subjected to live load from very heavy (gross weight > 80 tons) transport vehicles was calculated. The optimal proof load level was identified as leading to a positive expected benefit gain to the decision maker while also satisfying target reliability criteria for remaining service life. The analysis was performed for the evaluation of bridge performance with respect to five classifications of very heavy transport vehicles with different vehicle weights and configurations. T2 - 10th International Conference on Bridge Maintenance, Safety and Management (IABMAS) CY - Sapporo, Japan DA - 11.04.2021 KW - Proof load testing KW - Probabilistic decision analysis KW - Bridge resistance model PY - 2021 SN - 978-0-429-27911-9 DO - https://doi.org/10.1201/9780429279119-104 SP - 789 EP - 797 PB - CRC Press CY - Boca Raton, Florida AN - OPUS4-57879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Thöns, Sebastian T1 - Monitoring based condition assessment of offshore wind turbine support structures N2 - A central societal need in developed countries is the energy production with a low environmental impact. Thus ambitious energy programs have been initiated aiming at the establishment of renewable energies as a main contributor to the energy mix in the next decade. Like no other renewable energy, the offshore wind energy possesses a high potential and constitutes the main contributor to this aim. The development of large scale wind parks is one of the major challenges in the offshore industry today while the first wind parks of significant size and in considerable water depths are being built. In preparation for the next step, this thesis aims to contribute to the efficient and cost effective operation of wind parks. It specifically addresses the support of the inspection and maintenance activities of offshore wind turbines by the development of methods for the assessment and monitoring of support structures. The essential finding of this thesis is that the operation efficiency of wind turbine structures can be significantly enlarged by monitoring based assessment procedures. It is found that a substantial expected life-cycle benefit for the operation can be achieved by the conceptual integration of structural monitoring techniques in the structural reliability theory. The integration should be bidirectional in the sense that the generic design decisions for structural monitoring systems are based on a structural reliability assessment and that simultaneously a possible reduction of the uncertainty associated with the condition is utilized for the structural reliability assessment and thus for the inspection and maintenance planning. The thesis covers the issues of (I) the integration of monitoring data in the framework for structural reliability assessment of the Joint Committee on Structural Safety (JCSS), (II) the issue of the consistent determination of the measurement uncertainties utilizing all available information of the measurement process, (III) the issue of the application of monitoring techniques for structural integrity management and (IV) the establishment of a full probabilistic performance model basis for the support structure of an offshore wind turbine. To cover these issues the thesis comprises (1) the development of probabilistic structural, loading and limit state models, (2) a response surface algorithm for a multiple component reliability analysis, (3) a reliability analysis of an offshore wind turbine support structure applying the model basis, (4) a framework for the determination of measurement uncertainties utilizing process and observation data and (5) concepts for utilizing monitoring data in a structural reliability analysis as well as for the risk based inspection planning. The starting point of this thesis is the development of the model basis containing the models for the structural performance of a reference case, namely a support structure of an offshore wind turbine. The model basis comprises the structural, loading and probabilistic characterization of the ultimate, fatigue and the serviceability limit states and is derived considering the constitutive physical equations. The introduced models for the structural performance and loads account for design, production and execution information. A sensitivity study is performed on the basis of a non-linear coefficient of correlation. The process of establishing and analyzing these models contributes to an enhanced understanding of the performance of the structure and is documented in detail. The reliability analysis of an offshore wind turbine support structure builds upon the developed model basis. In order to facilitate the reliability analysis with such complex multiple component models, an adaptive response surface algorithm is developed. This algorithm utilizes clustered experimental designs in combination with an efficient augmentation scheme for these designs. The results of the reliability analyses comprise the system reliabilities and the probabilities of failure for the components in the individual limit states. With these results critical components are identified. A comparison with the target reliabilities specified in DIN EN 1990 (2002) shows that the target reliabilities are met. A novel contribution, as mentioned above, constitutes a new approach for the determination of measurement uncertainties in the context of the structural reliability theory. This approach builds upon two types of measurement uncertainties (as defined in the ISO/IEC Guide 98-3 (2008a)), namely the uncertainty based on a statistical analysis of observations and the uncertainty derived from a process equation describing physically the measurement process. Both types of measurement uncertainties are utilized 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. The measurement uncertainty models derived are analyzed through a sensitivity study and are discussed in detail resulting in an identification of the most relevant sources of measurement uncertainties. For the utilization of monitoring data in a structural reliability analysis the approach for the determination of measurement uncertainties data is applied. Monitoring data can be interpreted in two ways, namely as probabilistic loading model information and as probabilistic resistance model information, i.e. proof loading. For both ways the influence of the measurement uncertainties on the structural reliability is shown and how the specific modeling of monitoring data in a reliability analysis can result in a reduction of uncertainties and as a consequence in an increase of the reliability. The proof loading concept is developed further to account for probabilistic proof loading information, i.e. information subjected to measurement uncertainties. In conjunction with an alternative proof loading concept utilizing Bayesian updating techniques, a criterion to facilitate a consistent choice of the appropriate proof loading method is developed. The developed approaches and the findings are applied in a life-cycle cost-benefit analysis comprising the expected costs of failure, of inspection, of repair and of the monitoring system as well as its operation. Here, concepts for the design decision support of monitoring systems are introduced by formulating the life-cycle cost-benefit analysis as an optimization problem. On this basis, it can be determined which components should be monitored to achieve a life cycle benefit. Furthermore, an approach for the reduction of monitoring period is introduced. The most significant result of the cost-benefit analysis is that a substantial expected life-cycle benefit is achievable by the application of the developed concepts. KW - Structural condition assessment KW - Monitoring KW - Offshore wind turbine KW - Measurement uncertainty KW - Cost benefit analysis KW - Structural integrity management PY - 2012 DO - https://doi.org/10.3929/ethz-a-009753058 SN - 0257-6821 IS - 345 SP - 1 EP - 149 PB - vdf Hochschulverlag AG CY - Zollikon AN - OPUS4-28280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Berchtold, Florian A1 - Knaust, Christian A1 - Rogge, Andreas A1 - Arnold, L. A1 - Thöns, Sebastian ED - Lönnermark, Anders ED - Ingason, Haukur T1 - Risk Analysis for Road Tunnels – A Metamodel to Efficiently Integrate Complex Fire Scenarios N2 - Fires in road tunnels constitute complex scenarios with interactions between the fire, tunnel users and safety measures. More and more methodologies for risk analysis quantify the consequences of these scenarios with complex models. Examples for complex models are the computational fluid dynamics model Fire Dynamics Simulator (FDS) and the microscopic evacuation model FDS+Evac. However, the high computational effort of complex models often limits the number of scenarios in practice. To balance this drawback, the scenarios are often simplified. Accordingly, there is a challenge to consider complex scenarios in risk analysis. To face this challenge, we improved the metamodel used in the methodology for risk analysis presented on ISTSS 2016. In general, a metamodel quickly interpolates the consequences of few scenarios simulated with the complex models to a large number of arbitrary scenarios used in risk analysis. Now, our metamodel consists of the projection array-based design, the moving least squares method, and the prediction interval to quantify the metamodel uncertainty. Additionally, we adapted the projection array-based design in two ways: the focus of the sequential refinement on regions with high metamodel uncertainties; and the combination of two experimental designs for FDS and FDS+Evac. To scrutinise the metamodel, we analysed the effects of three sequential refinement steps on the metamodel itself and on the results of risk analysis. We observed convergence in both after the second step (ten scenarios in FDS, 192 scenarios in FDS+Evac). In comparison to ISTSS 2016, we then ran 20 scenarios in FDS and 800 scenarios in FDS+Evac. Thus, we reduced the number of scenarios remarkably with the improved metamodel. In conclusion, we can now efficiently integrate complex scenarios in risk analysis. We further emphasise that the metamodel is broadly applicable on various experimental or modelling issues in fire safety engineering. T2 - International Symposium on Tunnel Safety and Security CY - Boras, Sweden DA - 14.03.2018 KW - Risk KW - Metamodel KW - CFD KW - Evacuation KW - Uncertainty PY - 2018 SN - 978-91-88695-48-2 VL - 8 SP - 349 EP - 360 AN - OPUS4-44535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Long, Lijia A1 - Thöns, Sebastian A1 - Döhler, M. T1 - The effects of SHM system parameters on the value of damage detection information N2 - This paper addresses how the value of damage detection Information depends on key Parameters of the Structural Health Monitoring (SHM) system including number of sensors and sensor locations. The Damage Detection System (DDS) provides the information by comparing ambient vibration measurements of a (healthy) reference state with measurements of the current structural system. The performance of DDS method depends on the physical measurement properties such as the number of sensors, sensor positions, measuring length and sensor type, measurement noise, ambient excitation and sampling frequency, as well as on the data processing algorithm including the chosen type I error for the indication threshold. The quantification of the value of Information (VoI) is an expected utility based Bayesian decision analysis method for quantifying the difference of the expected economic benefits with and without information. The (pre-)posterior probability is computed utilizing the Bayesian updating theorem for all possible indications. If changing any key parameters of DDS, the updated probability of system failure given damage detection information will be varied due to different indication of probability of damage, which will result in changes of value of damage detection information. The DDS system is applied in a statically determinate Pratt truss bridge girder. Through the analysis of the value of information with different SHM system characteristics, the settings of DDS can be optimized for minimum expected costs and risks before implementation. T2 - 9th European Workshop on Structural Health Monitoring CY - Manchester, UK DA - 10.07.2018 KW - SHM KW - Damage detection system KW - Value of information PY - 2018 SP - 375 EP - 384 AN - OPUS4-46190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Long, Lijia A1 - Thöns, Sebastian A1 - Döhler, M. T1 - Damage Detection and Deteriorating Structural Systems N2 - This paper addresses the quantification of the value of damage detection system and algorithm information on the basis of Value of Information (VoI) analysis to enhance the benefit of damage detection information by providing the basis for its optimization before it is performed and implemented. The approach of the quantification the value of damage detection information builds upon the Bayesian decision theory facilitating the utilization of damage detection performance models, which describe the information and its precision on structural system level, facilitating actions to ensure the structural integrity and facilitating to describe the structural system performance and its functionality throughout the service life. The structural system performance is described with its functionality, its deterioration and its behavior under extreme loading. The structural system reliability given the damage detection information is determined utilizing Bayesian updating. The damage detection performance is described with the probability of indication for different component and system damage states taking into account type 1 and type 2 errors. The value of damage detection information is then calculated as the difference between the expected benefits and risks utilizing the damage detection information or not. With an application example of the developed approach based on a deteriorating Pratt truss system, the value of damage detection information is determined,demonstrating the potential of risk reduction and expected cost reduction. T2 - International Workshop on Structural Health Monitoring CY - Stanford, CA, USA DA - 12.09.2017 KW - Reliability updating KW - Structural reliability and risks KW - Damage detection KW - Value of information PY - 2017 SN - 978-1-60595-330-4 SP - 1276 EP - 1284 AN - OPUS4-43624 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Long, Lijia T1 - The effects of SHM system parameters on the value of damage detection information N2 - This paper addresses how the value of damage detection Information depends on key Parameters of the Structural Health Monitoring (SHM) system including number of sensors and sensor locations. The Damage Detection System (DDS) provides the information by comparing ambient vibration measurements of a (healthy) reference state with measurements of the current structural system. The performance of DDS method depends on the physical measurement properties such as the number of sensors, sensor positions, measuring length and sensor type, measurement noise, ambient excitation and sampling frequency, as well as on the data processing algorithm including the chosen type I error for the indication threshold. The quantification of the value of Information (VoI) is an expected utility based Bayesian decision analysis method for quantifying the difference of the expected economic benefits with and without information. The (pre-)posterior probability is computed utilizing the Bayesian updating theorem for all possible indications. If changing any key parameters of DDS, the updated probability of system failure given damage detection information will be varied due to different indication of probability of damage, which will result in changes of value of damage detection information. The DDS system is applied in a statically determinate Pratt truss bridge girder. Through the analysis of the value of information with different SHM system characteristics, the settings of DDS can be optimized for minimum expected costs and risks before implementation. T2 - PhD day 2018 CY - BAM, Berlin, Germany DA - 31.05.2018 KW - SHM KW - Damage detection system KW - Value of information PY - 2018 AN - OPUS4-46192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -