@article{Staat2005, author = {Staat, Manfred}, title = {Direct finite element route for design-by-analysis of pressure components}, year = {2005}, abstract = {In the new European standard for unfired pressure vessels, EN 13445-3, there are two approaches for carrying out a Design-by-Analysis that cover both the stress categorization method (Annex C) and the direct route method (Annex B) for a check against global plastic deformation and against progressive plastic deformation. This paper presents the direct route in the language of limit and shakedown analysis. This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for mechanical and thermal actions. One observation from the examples is that the so-called 3f (3Sm) criterion fails to be a reliable check against progressive plastic deformation. Precise conditions are given, which greatly restrict the applicability of the 3f criterion.}, subject = {Einspielen }, language = {en} } @article{Staat2003, author = {Staat, Manfred}, title = {Shakedown and ratchetting under tension-torsion loadings: analysis and experiments}, year = {2003}, abstract = {Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis.}, subject = {Einspielen }, language = {en} } @article{Staat2000, author = {Staat, Manfred}, title = {Basis Reduction for the Shakedown Problem for Bounded Kinematic Hardening Material}, year = {2000}, abstract = {Limit and shakedown analysis are effective methods for assessing the load carrying capacity of a given structure. The elasto-plastic behavior of the structure subjected to loads varying in a given load domain is characterized by the shakedown load factor, defined as the maximum factor which satisfies the sufficient conditions stated in the corresponding static shakedown theorem. The finite element dicretization of the problem may lead to very large convex optimization. For the effective solution a basis reduction method has been developed that makes use of the special problem structure for perfectly plastic material. The paper proposes a modified basis reduction method for direct application to the two-surface plasticity model of bounded kinematic hardening material. The considered numerical examples show an enlargement of the load carrying capacity due to bounded hardening.}, subject = {Finite-Elemente-Methode}, language = {en} } @inproceedings{Staat2003, author = {Staat, Manfred}, title = {Design by Analysis of Pressure Components by non-linear Optimization}, year = {2003}, abstract = {This paper presents the direct route to Design by Analysis (DBA) of the new European pressure vessel standard in the language of limit and shakedown analysis (LISA). This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for some examples from the DBA-Manual. One observation from the examples is, that the optimisation approach gives reliable and close lower bound solutions leading to simple and optimised design decision.}, language = {en} } @article{Staat2001, author = {Staat, Manfred}, title = {LISA - a European project for FEM-based limit and shakedown analysis}, year = {2001}, abstract = {The load-carrying capacity or the safety against plastic limit states are the central questions in the design of structures and passive components in the apparatus engineering. A precise answer is most simply given by limit and shakedown analysis. These methods can be based on static and kinematic theorems for lower and upper bound analysis. Both may be formulated as optimization problems for finite element discretizations of structures. The problems of large-scale analysis and the extension towards realistic material modelling will be solved in a European research project. Limit and shakedown analyses are briefly demonstrated with illustrative examples.}, subject = {Einspielen }, language = {en} } @article{Staat2000, author = {Staat, Manfred}, title = {Direct FEM Limit and Shakedown Analysis with Uncertain Data}, year = {2000}, abstract = {The structural reliability with respect to plastic collapse or to inadaptation is formulated on the basis of the lower bound limit and shakedown theorems. A direct definition of the limit state function is achieved which permits the use of the highly effective first order reliability methods (FORM) is achieved. The theorems are implemented into a general purpose FEM program in a way capable of large-scale analysis. The limit state function and its gradient are obtained from a mathematical optimization problem. This direct approach reduces considerably the necessary knowledge of uncertain technological input data, the computing time, and the numerical error, leading to highly effective and precise reliability analyses.}, subject = {Finite-Elemente-Methode}, language = {en} } @misc{Staat2006, author = {Staat, Manfred}, title = {Engineering Mechanics. Lecture Notes. 2nd edition, translation of the 3rd corrected and extended German edition of "Technische Mechanik"}, year = {2006}, abstract = {English translation of the corrected lectures notes of Sebastian Kr{\"a}mer. Contents 0 Introduction to Mechanics 1 Statics of Rigid Bodies 2 Elastostatics (Strength of Materials) 3 Kinematics 4 Kinetics Literature}, subject = {Technische Mechanik}, language = {en} } @inproceedings{Staat2006, author = {Staat, Manfred}, title = {Problems and chances for probabilistic fracture mechanics in the analysis of steel pressure boundary reliability. - {\"U}berarb. Ausg.}, year = {2006}, abstract = {In: Technical feasibility and reliability of passive safety systems for nuclear power plants. Proceedings of an Advisory Group Meeting held in J{\"u}lich, 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.}, subject = {Bruchmechanik}, language = {en} } @article{Staat2012, author = {Staat, Manfred}, title = {Limit and shakedown analysis under uncertainty}, series = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, volume = {19}, journal = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, pages = {45 -- 47}, year = {2012}, language = {en} } @article{Staat2021, author = {Staat, Manfred}, title = {An extension strain type Mohr-Coulomb criterion}, series = {Rock mechanics and rock engineering}, volume = {54}, journal = {Rock mechanics and rock engineering}, number = {12}, publisher = {Springer Nature}, address = {Cham}, issn = {1434-453X}, doi = {10.1007/s00603-021-02608-7}, pages = {6207 -- 6233}, year = {2021}, abstract = {Extension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. In this article, it is shown that the simple extension strain criterion makes unrealistic strength predictions in biaxial compression and tension. To overcome this major limitation, a new extension strain criterion is proposed by adding a weighted principal shear component to the simple criterion. The shear weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr-Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting extension failure modes, which are unexpected in the classical understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain leading to dilatancy. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak stress CP. Different from compressive loading, tensile loading requires only a limited number of critical cracks to cause failure. Therefore, for tensile stresses, the failure criteria must be modified somehow, possibly by a cut-off corresponding to the CI stress. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion.}, language = {en} } @article{SrnanekGeurtsLentzeetal.2004, author = {Srnanek, R. and Geurts, J. and Lentze, M. and Irmer, G. and Donoval, D. and Brdecka, P. and Kordos, P. and F{\"o}rster, Arnold and Sciana, B. and Radziewicz, D. and Tlaczala, M.}, title = {Study of d-doped GaAs layers by micro-Raman spectroscopy on bevelled samples}, series = {Applied surface science . 230 (2004), H. 1 -4}, journal = {Applied surface science . 230 (2004), H. 1 -4}, isbn = {0169-4332}, pages = {379 -- 385}, year = {2004}, language = {en} } @inproceedings{SrivastavaSinghDhandetal.2006, author = {Srivastava, Alok and Singh, Virendra and Dhand, Chetna and Kaur, Manindar and Singh, Tejvir and Witte, Katrin and Scherer, Ulrich W.}, title = {Study of swift heavy ion modified conduction polymer composites for application as gas sensor}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1345}, year = {2006}, abstract = {A polyaniline-based conducting composite was prepared by oxidative polymerisation of aniline in a polyvinylchloride (PVC) matrix. The coherent free standing thin films of the composite were prepared by a solution casting method. The polyvinyl chloride-polyaniline composites exposed to 120 MeV ions of silicon with total ion fluence ranging from 1011 to 1013 ions/cm2, were observed to be more sensitive towards ammonia gas than the unirradiated composite. The response time of the irradiated composites was observed to be comparably shorter. We report for the first time the application of swift heavy ion modified insulating polymer conducting polymer (IPCP) composites for sensing of ammonia gas.}, subject = {Biosensor}, language = {en} } @incollection{SrivastavaKnolleHoyleretal.2015, author = {Srivastava, Alok and Knolle, Friedhart and Hoyler, Friedrich and Scherer, Ulrich W. and Schnug, Ewald}, title = {Uranium Toxicity in the State of Punjab in North-Western India}, series = {Management of Natural Resources in a Changing Environment}, booktitle = {Management of Natural Resources in a Changing Environment}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-12559-6}, doi = {10.1007/978-3-319-12559-6_21}, pages = {271 -- 275}, year = {2015}, abstract = {Lately there has been an increasing concern about uranium toxicity in some districts of Punjab State located in the North Western part of India after the publication of a report (Blaurock-Busch et al. 2010) which showed that the concentration of uranium in hair and urine of children suffering from physical deformities, neurological and mental disorder from Malwa region (Fig. 1) of Punjab State was manifold higher than the reference ranges. A train which connects the affected region with the nearby city of Bikaner which has a Cancer Hospital has been nicknamed as Cancer Express due to the frenzy generated on account of uranium related toxicity.}, language = {en} } @article{SrivastavaSinghAggarwaletal.2010, author = {Srivastava, A. and Singh, V. and Aggarwal, P. and Schneeweiss, F. and Scherer, Ulrich W. and Friedrich, W.}, title = {Optical studies of insulating polymers for radiation dose monitoring}, series = {Indian Journal of Pure \& Applied Physics}, volume = {48}, journal = {Indian Journal of Pure \& Applied Physics}, number = {11}, isbn = {0019-5596}, pages = {782 -- 786}, year = {2010}, language = {en} } @article{SrivastavaLahiriMaitietal.2014, author = {Srivastava, A. and Lahiri, S. and Maiti, M. and Knolle, F. and Hoyler, Friedrich and Scherer, Ulrich W. and Schnug, E. W.}, title = {Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India}, series = {Journal of Radioanalytical and Nuclear Chemistry}, volume = {2014}, journal = {Journal of Radioanalytical and Nuclear Chemistry}, number = {302}, publisher = {Springer Nature}, address = {Basel}, issn = {1588-2780 (E-Journal); 0022-4081 (Print); 0134-0719 (Print); 0236-5731 (Print); 1417-2097 (Print)}, doi = {0.1007/s10967-014-3450-1}, pages = {1049 -- 1052}, year = {2014}, language = {en} } @article{SrivastavaChaharSharmaetal.2017, author = {Srivastava, A. and Chahar, V. and Sharma, V. and Sun, Y. and Bol, R. and Knolle, F. and Schnug, E. and Hoyler, Friedrich and Naskar, N. and Lahiri, S. and Patnaik, R.}, title = {Study of uranium toxicity using low-background gamma-ray spectrometry}, series = {Journal of Radioanalytical and Nuclear Chemistry}, journal = {Journal of Radioanalytical and Nuclear Chemistry}, number = {Online first}, publisher = {Springer}, address = {Berlin}, issn = {1588-2780}, doi = {10.1007/s10967-017-5466-9}, pages = {1 -- 7}, year = {2017}, language = {en} } @inproceedings{SpaeteHafnerSchwarzer2000, author = {Sp{\"a}te, Frank and Hafner, B. and Schwarzer, Klemens}, title = {A system for solar process heat for decentralized applications in developing countries}, series = {ISES 1999 Solar World Congress, Jerusalem, Israel, July 4-9, 1999 : conference proceedings / ed. Gershon Grossman. Vol. 3}, booktitle = {ISES 1999 Solar World Congress, Jerusalem, Israel, July 4-9, 1999 : conference proceedings / ed. Gershon Grossman. Vol. 3}, publisher = {Elsevier}, address = {Oxford}, isbn = {0-080-043895-4}, pages = {236 -- 291}, year = {2000}, language = {en} } @article{SpaeteFaberSchwarzeretal.2004, author = {Sp{\"a}te, Frank and Faber, Christian and Schwarzer, Klemens and Hartz, Thomas}, title = {Comparison of solar hot water systems in solar settlements - decentralized or centralized systems?}, series = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 1}, journal = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 1}, publisher = {PSE}, address = {Freiburg [Breisgau]}, isbn = {3-9809656-1-9}, pages = {1-666-1-671}, year = {2004}, language = {en} } @inproceedings{SpurmannOhndorfDachwaldetal.2009, author = {Spurmann, J{\"o}rn and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and L{\"o}b, Horst and Schartner, Karl-Heinz}, title = {Interplanetary trajectory optimization for a sep mission to Saturn}, series = {60th International Astronautical Congress 2009}, booktitle = {60th International Astronautical Congress 2009}, isbn = {9781615679089}, pages = {5234 -- 5248}, year = {2009}, abstract = {The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.}, language = {en} } @misc{SponagelWachowitz1992, author = {Sponagel, Stefan and Wachowitz, Waldemar}, title = {Shaft seal : United States Patent 5,143,385 ; date of patent: Sep. 1, 1992 / assignee: Firma Carl Freudenberg}, publisher = {[United States Patent and Trademark Office]}, address = {[Alexandria, VA]}, pages = {5 S. : Ill.}, year = {1992}, language = {en} }