TY - CHAP A1 - Staat, Manfred T1 - Problems and chances for probabilistic fracture mechanics in the analysis of steel pressure boundary reliability. - Überarb. Ausg. N2 - In: Technical feasibility and reliability of passive safety systems for nuclear power plants. Proceedings of an Advisory Group Meeting held in Jülich, 21-24 November 1994. - Vienna , 1996. - Seite: 43 - 55 IAEA-TECDOC-920 Abstract: It is shown that the difficulty for probabilistic fracture mechanics (PFM) is the general problem of the high reliability of a small population. There is no way around the problem as yet. Therefore what PFM can contribute to the reliability of steel pressure boundaries is demon­strated with the example of a typical reactor pressure vessel and critically discussed. Although no method is distinguishable that could give exact failure probabilities, PFM has several addi­tional chances. Upper limits for failure probability may be obtained together with trends for design and operating conditions. Further, PFM can identify the most sensitive parameters, improved control of which would increase reliability. Thus PFM should play a vital role in the analysis of steel pressure boundaries despite all shortcomings. KW - Bruchmechanik KW - probabilistic fracture mechanics KW - PFM Y1 - 2006 ER - TY - CHAP A1 - Tran, Thanh Ngoc A1 - Staat, Manfred A1 - Kreißig, R. T1 - Calculation of load carrying capacity of shell structures with elasto-plastic material by direct methods N2 - Proceedings of the International Conference on Material Theory and Nonlinear Dynamics. MatDyn. Hanoi, Vietnam, Sept. 24-26, 2007, 8 p. In this paper, a method is introduced to determine the limit load of general shells using the finite element method. The method is based on an upper bound limit and shakedown analysis with elastic-perfectly plastic material model. A non-linear constrained optimisation problem is solved by using Newton’s method in conjunction with a penalty method and the Lagrangean dual method. Numerical investigation of a pipe bend subjected to bending moments proves the effectiveness of the algorithm. KW - Finite-Elemente-Methode Y1 - 2007 ER - TY - JOUR A1 - Schopp, Christoph A1 - Britun, Nikolay A1 - Vorac, Jan A1 - Synek, Petr A1 - Snyders, Rony A1 - Heuermann, Holger T1 - Thermal and Optical Study on the Frequency Dependence of an Atmospheric Microwave Argon Plasma Jet JF - IEEE Transactions on Plasma Science Y1 - 2019 SN - 1939-9375 VL - 47 IS - 7 SP - 3176 EP - 3181 PB - IEEE CY - New York ER - TY - JOUR A1 - Staat, Manfred A1 - Heitzer, M. T1 - Structural Reliability Analysis of Elasto-Plastic Structures JF - Safety and reliability : proceedings of ESREL '99, the Tenth European Conference on Safety and Reliability, Munich-Garching, Germany, 13 - 17 September 1999 / Schuëller, G. I.; Kafka, P. [eds] Y1 - 1999 SN - 90-5809-109-0 SP - 513 EP - 518 PB - Balkema CY - Rotterdam ER - TY - CHAP A1 - Tran, Thanh Ngoc A1 - Novacek, V. A1 - Tolba, R. A1 - Klinge, U. A1 - Turquier, F. A1 - Staat, Manfred T1 - Experimental and Computational approach to study colorectal anastomosis. ISB2011, Proceedings of the XXIII Congress of the International Society of Biomechanics, Brussels, Belgium, July 3-7, 2011 N2 - Summary: This paper presents a methodology to study and understand the mechanics of stapled anastomotic behaviors by combining empirical experimentation and finite element analysis. Performance of stapled anastomosis is studied in terms of leakage and numerical results which are compared to in vitro experiments performed on fresh porcine tissue. Results suggest that leaks occur between the tissue and staple legs penetrating through the tissue. KW - Anastomose KW - Finite-Elemente-Methode KW - Biomechanik KW - Anastomosis KW - Finite element method KW - Biomechanics Y1 - 2011 ER - TY - CHAP A1 - Mertens, Alexander A1 - Brauner, Philipp A1 - Baier, Ralph A1 - Brillowski, Florian A1 - Dammers, Hannah A1 - van Dyck, Marc A1 - Kong, Iris A1 - Königs, Peter A1 - Kordtomeikel, Frauke A1 - Liehner, Gian Luca A1 - Pütz, Sebastian A1 - Rodermann, Niklas A1 - Schaar, Anne Kathrin A1 - Steuer-Dankert, Linda A1 - Vervier, Luisa A1 - Wlecke, Shari A1 - Gries, Thomas A1 - Leicht-Scholten, Carmen A1 - Nagel, Saskia K. A1 - Piller, Frank T. A1 - Schuh, Günther A1 - Ziefle, Martina A1 - Nitsch, Verena ED - Michael, Judith ED - Pfeiffer, Jérôme ED - Wortmann, Andreas T1 - Modelling Human Factors in Cyber Physical Production Systems by the Integration of Human Digital Shadows T2 - Modellierung 2022 Satellite Events N2 - 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. KW - human digital shadow KW - cyber physical production system KW - human factors Y1 - 2022 U6 - https://doi.org/10.18420/modellierung2022ws-018 N1 - Modellierung 2022, 27. Juni - 01. Juli 2022, Hamburg, Deutschland SP - 147 EP - 149 PB - GI Gesellschaft für Informatik CY - Bonn ER - TY - JOUR A1 - Butenweg, Christoph A1 - Bursi, Oreste S. A1 - Paolacci, Fabrizio A1 - Marinković, Marko A1 - Lanese, Igor A1 - Nardin, Chiara A1 - Quinci, Gianluca ED - Yang, J. T1 - Seismic performance of an industrial multi-storey frame structure with process equipment subjected to shake table testing JF - Engineering Structures N2 - Past earthquakes demonstrated the high vulnerability of industrial facilities equipped with complex process technologies leading to serious damage of process equipment and multiple and simultaneous release of hazardous substances. Nonetheless, current standards for seismic design of industrial facilities are considered inadequate to guarantee proper safety conditions against exceptional events entailing loss of containment and related consequences. On these premises, the 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. In detail, the objective of the SPIF project is the investigation of the seismic behaviour of a representative industrial multi-storey frame structure equipped with complex process components by means of shaking table tests. Along this main vein and in a performance-based design perspective, the issues investigated in depth are the interaction between a primary moment resisting frame (MRF) steel structure and secondary process components that influence the performance of the whole system; and a proper check of floor spectra predictions. The evaluation of experimental data clearly shows a favourable performance of the MRF structure, some weaknesses of local details due to the interaction between floor crossbeams and process components and, finally, the overconservatism of current design standards w.r.t. floor spectra predictions. KW - Multi-storey KW - Frame structure KW - Earthquake KW - Tank KW - Piping Y1 - 2021 U6 - https://doi.org/10.1016/j.engstruct.2021.112681 SN - 0141-0296 VL - 243 IS - 15 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kleefeld, Andreas A1 - Reißel, Martin T1 - The Levenberg–Marquardt method applied to a parameter estimation problem arising from electrical resistivity tomography JF - Applied Mathematics and Computation Y1 - 2011 SN - 0096-3003 VL - 217 IS - 9 SP - 4490 EP - 4501 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Baader, Fabian A1 - Keller, Denis A1 - Lehmann, Raphael A1 - Gerber, Lukas A1 - Reiswich, Martin A1 - Dachwald, Bernd A1 - Förstner, Roger T1 - Operating melting probes for ice penetration under sublimation conditions and in reduced gravity on a sounding rocket T2 - Proceedings of the 24th ESA Symposium on European Rocket and Balloon Programmes and related Research Y1 - 2019 SN - 0379-6566 N1 - 24th PAC Symposium 2019 ER - TY - CHAP A1 - Borggräfe, Andreas A1 - Dachwald, Bernd T1 - Mission performance evaluation for solar sails using a refined SRP force model with variable optical coefficients T2 - 2nd International Symposium on Solar Sailing N2 - Solar sails provide ignificant advantages over other low-thrust propulsion systems because they produce thrust by the momentum exchange from solar radiation pressure (SRP) and thus do not consume any propellant.The force exerted on a very thin sail foil basically depends on the light incidence angle. Several analytical SRP force models that describe the SRP force acting on the sail have been established since the 1970s. All the widely used models use constant optical force coefficients of the reflecting sail material. In 2006,MENGALI et al. proposed a refined SRP force model that takes into account the dependancy of the force coefficients on the light incident angle,the sail’s distance from the sun (and thus the sail emperature) and the surface roughness of the sail material [1]. In this paper, the refined SRP force model is compared to the previous ones in order to identify the potential impact of the new model on the predicted capabilities of solar sails in performing low-cost interplanetary space missions. All force models have been implemented within InTrance, a global low-thrust trajectory optimization software utilizing evolutionary neurocontrol [2]. Two interplanetary rendezvous missions, to Mercury and the near-Earth asteroid 1996FG3, are investigated. Two solar sail performances in terms of characteristic acceleration are examined for both scenarios, 0.2 mm/s2 and 0.5 mm/s2, termed “low” and “medium” sail performance. In case of the refined SRP model, three different values of surface roughness are chosen, h = 0 nm, 10 nm and 25 nm. The results show that the refined SRP force model yields shorter transfer times than the standard model. Y1 - 2010 N1 - 2nd International Symposium on Solar Sailing, ISSS 2010, 2010-07-20 - 2010-07-22. New York City College of Technology of the City University of New York, USA SP - 1 EP - 6 ER -