TY - JOUR A1 - Staat, Manfred T1 - Some Achievements of the European Project LISA for FEM Based Limit and Shakedown Analysis JF - Computational mechanics : developments and applications, 2002 : presented at the 2002 ASME Pressure Vessels and Piping Conference, Vancouver, British Columbia, Canada, August 5 - 9. / Badie, N. [ed] Y1 - 2002 SN - 0791846520 N1 - Serie PVP ; vol. 441. SP - 177 EP - 185 PB - American Society of Mechanical Engineers CY - New York ER - TY - GEN A1 - Staat, Manfred T1 - Engineering Mechanics. Lecture Notes. 2nd edition, translation of the 3rd corrected and extended German edition of "Technische Mechanik" N2 - English translation of the corrected lectures notes of Sebastian Krämer. Contents 0 Introduction to Mechanics 1 Statics of Rigid Bodies 2 Elastostatics (Strength of Materials) 3 Kinematics 4 Kinetics Literature KW - Technische Mechanik KW - Mechanics KW - Statics KW - Elastostatics KW - Kinematics KW - Kinetics Y1 - 2006 ER - 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 - JOUR A1 - Staat, Manfred T1 - Cyclic plastic deformation tests to verify FEM-based shakedown analyses N2 - Fatigue analyses are conducted with the aim of verifying that thermal ratcheting is limited. To this end it is important to make a clear distintion between the shakedown range and the ratcheting range (continuing deformation). As part of an EU-supported research project, experiments were carried out using a 4-bar model. The experiment comprised a water-cooled internal tube, and three insulated heatable outer test bars. The system was subjected to alternating axial forces, superimposed with alternating temperatures at the outer bars. The test parameters were partly selected on the basis of previous shakedown analyses. During the test, temperatures and strains were measured as a function of time. The loads and the resulting stresses were confirmed on an ongoing basis during performance of the test, and after it. Different material models were applied for this incremental elasto-plastic analysis using the ANSYS program. The results of the simulation are used to verify the FEM-based shakedown analysis. KW - Materialermüdung KW - Einspielen KW - Materialermüdung KW - shakedown analyses KW - thermal ratcheting KW - fatigue analyses Y1 - 2001 ER - TY - JOUR A1 - Staat, Manfred T1 - Direct FEM Limit and Shakedown Analysis with Uncertain Data N2 - 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. KW - Finite-Elemente-Methode KW - Einspielen KW - FEM KW - Einspielanalyse KW - shakedown KW - limit load KW - reliability analysis KW - FEM KW - direct method Y1 - 2000 ER - TY - JOUR A1 - Staat, Manfred T1 - Basis Reduction for the Shakedown Problem for Bounded Kinematic Hardening Material N2 - 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. KW - Finite-Elemente-Methode KW - Einspielen KW - Basis Reduktion KW - konvexe Optimierung KW - FEM KW - Druckgeräte KW - Basis reduction KW - Convex optimization KW - FEM KW - Shakedown analysis Y1 - 2000 ER - TY - JOUR A1 - Staat, Manfred T1 - LISA - a European project for FEM-based limit and shakedown analysis N2 - 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. KW - Einspielen KW - Traglast KW - Finite-Elemente-Methode KW - Traglastanalyse KW - Einspielanalyse KW - FEM KW - limit analysis KW - shakedown analysis Y1 - 2001 ER - TY - JOUR A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty JF - International journal of computational methods : IJCM Y1 - 2013 SN - 0219-8762 SP - Publ. online PB - World Scientific Publishing CY - Singapore ER - TY - JOUR A1 - Staat, Manfred T1 - Sensitivity of and Influences on the Reliability of an HTR-Module Primary Circuit Pressure Boundary JF - Transactions of the 12th International Conference on Structural Mechanics in Reactor Technology (SMiRT-12) / Kussmaul, K. [ed] Y1 - 1993 SN - 0-444-81515-5 N1 - Vol. M, Paper MG10/2 SP - 147 EP - 152 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Staat, Manfred T1 - Problems and Chances for Probabilistic Fracture Mechanics in the Analysis of Steel Pressure Boundary Reliability JF - 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 Y1 - 1996 N1 - IAEA-TECDOC-920 ; Onlinezugriff erfolgt auf die überarb. Ausg. 2006 SP - 43 EP - 55 CY - Vienna ER - TY - JOUR A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty JF - Tap chi Khoa hoc & ung dung - Dai hoc Ton Duc Thang Y1 - 2012 N1 - = Journal of Applied Sciences - Ton Duc Thang University VL - 19 SP - 45 EP - 47 ER - TY - JOUR A1 - Staat, Manfred T1 - Probabilistic assessment of the fracture mechanics behaviour of an HTR-module primary circuit pressure boundary JF - Nuclear Engineering and Design. 160 (1996), H. 1-2 Y1 - 1996 SN - 0029-5493 SP - 221 EP - 236 ER - TY - JOUR A1 - Staat, Manfred T1 - Reliability of an HTR-module primary circuit pressure boundary Influences, sensitivity, and comparison with a PWR JF - Nuclear Engineering and Design. 158 (1995), H. 2-3 Y1 - 1995 SN - 0029-5493 SP - 333 EP - 340 ER - TY - JOUR A1 - Staat, Manfred T1 - An extension strain type Mohr–Coulomb criterion JF - Rock mechanics and rock engineering N2 - 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. Y1 - 2021 U6 - https://doi.org/10.1007/s00603-021-02608-7 SN - 1434-453X N1 - Corresponding author: Manfred Staat VL - 54 IS - 12 SP - 6207 EP - 6233 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Srnanek, R. A1 - Geurts, J. A1 - Lentze, M. A1 - Irmer, G. A1 - Donoval, D. A1 - Brdecka, P. A1 - Kordos, P. A1 - Förster, Arnold A1 - Sciana, B. A1 - Radziewicz, D. A1 - Tlaczala, M. T1 - Study of d-doped GaAs layers by micro-Raman spectroscopy on bevelled samples JF - Applied surface science . 230 (2004), H. 1 -4 Y1 - 2004 SN - 0169-4332 N1 - ISSN der E-Ausg.: 0169-4332 SP - 379 EP - 385 ER - TY - CHAP A1 - Srivastava, Alok A1 - Singh, Virendra A1 - Dhand, Chetna A1 - Kaur, Manindar A1 - Singh, Tejvir A1 - Witte, Katrin A1 - Scherer, Ulrich W. T1 - Study of swift heavy ion modified conduction polymer composites for application as gas sensor N2 - 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. KW - Biosensor KW - Conducing polymer KW - ammonia gas sensors KW - swift heavy ions KW - polymer composites Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1345 ER - TY - CHAP A1 - Srivastava, Alok A1 - Knolle, Friedhart A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, Ewald T1 - Uranium Toxicity in the State of Punjab in North-Western India T2 - Management of Natural Resources in a Changing Environment N2 - 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. Y1 - 2015 SN - 978-3-319-12559-6 U6 - https://doi.org/10.1007/978-3-319-12559-6_21 SP - 271 EP - 275 PB - Springer CY - Cham ER - TY - JOUR A1 - Srivastava, A. A1 - Singh, V. A1 - Aggarwal, P. A1 - Schneeweiss, F. A1 - Scherer, Ulrich W. A1 - Friedrich, W. T1 - Optical studies of insulating polymers for radiation dose monitoring JF - Indian Journal of Pure & Applied Physics Y1 - 2010 SN - 0019-5596 N1 - Special Issue: SI VL - 48 IS - 11 SP - 782 EP - 786 ER - TY - JOUR A1 - Srivastava, A. A1 - Lahiri, S. A1 - Maiti, M. A1 - Knolle, F. A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, E. W. T1 - Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India JF - Journal of Radioanalytical and Nuclear Chemistry Y1 - 2014 U6 - https://doi.org/0.1007/s10967-014-3450-1 SN - 1588-2780 (E-Journal); 0022-4081 (Print); 0134-0719 (Print); 0236-5731 (Print); 1417-2097 (Print) VL - 2014 IS - 302 SP - 1049 EP - 1052 PB - Springer Nature CY - Basel ER - TY - JOUR A1 - Srivastava, A. A1 - Chahar, V. A1 - Sharma, V. A1 - Sun, Y. A1 - Bol, R. A1 - Knolle, F. A1 - Schnug, E. A1 - Hoyler, Friedrich A1 - Naskar, N. A1 - Lahiri, S. A1 - Patnaik, R. T1 - Study of uranium toxicity using low-background gamma-ray spectrometry JF - Journal of Radioanalytical and Nuclear Chemistry Y1 - 2017 U6 - https://doi.org/10.1007/s10967-017-5466-9 SN - 1588-2780 IS - Online first SP - 1 EP - 7 PB - Springer CY - Berlin ER -