TY - CHAP A1 - Staat, Manfred A1 - Heitzer, Michael T1 - The restricted influence of kinematic hardening on shakedown loads N2 - Structural design analyses are conducted with the aim of verifying the exclusion of ratcheting. To this end it is important to make a clear distinction between the shakedown range and the ratcheting range. In cyclic plasticity more sophisticated hardening models have been suggested in order to model the strain evolution observed in ratcheting experiments. The hardening models used in shakedown analysis are comparatively simple. It is shown that shakedown analysis can make quite stable predictions of admissible load ranges despite the simplicity of the underlying hardening models. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis. Both give identical or similar shakedown ranges. Structural shakedown analyses show that the loading may have a more pronounced effect than the hardening model. KW - Biomedizinische Technik KW - Einspielen KW - Shakedown KW - Ratcheting KW - Bruchmechanik KW - shakedown KW - material shakedown KW - linear kinematic hardening KW - nonlinear kinematic hardening KW - ratchetting Y1 - 2002 ER - TY - CHAP A1 - Staat, Manfred A1 - Heitzer, Michael T1 - Direct static FEM approach to limit and shakedown analysis N2 - Safety and reliability of structures may be assessed indirectly by stress distributions. Limit and shakedown theorems are simplified but exact methods of plasticity that provide safety factors directly in the loading space. These theorems may be used for a direct definition of the limit state function for failure by plastic collapse or by inadaptation. In a FEM formulation the limit state function is obtained from a nonlinear optimization problem. This direct approach reduces considerably the necessary knowledge of uncertain technological input data, the computing time, and the numerical error. Moreover, the direct way leads to highly effective and precise reliability analyses. The theorems are implemented into a general purpose FEM program in a way capable of large-scale analysis. KW - Einspielen KW - Nichtlineare Optimierung KW - Shakedown KW - Shakedown KW - limit load KW - lower bound theorem KW - nonlinear optimization KW - reliability Y1 - 2000 ER - TY - JOUR A1 - Staat, Manfred T1 - Plastic collapse analysis of longitudinally flawed pipes and vessels N2 - Improved collapse loads of thick-walled, crack containing pipes and vessels are suggested. Very deep cracks have a residual strength which is better modelled by a global limit load. In all burst tests, the ductility of pressure vessel steels was sufficiently high whereby the burst pressure could be predicted by limit analysis with no need to apply fracture mechanics. The relative prognosis error increases however, for long and deep defects due to uncertainties of geometry and strength data. KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohr KW - Rohrbruch KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohrbruch KW - Fehlerstellen KW - pipes KW - vessels KW - load limit KW - burst tests KW - burst pressure KW - flaw Y1 - 2004 ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Schubert, J A1 - Kloock, Joachim P. A1 - Zander, W. A1 - Mourzina, Y. G. A1 - Legin, A. A1 - Vlasov, Y. G. A1 - Lüth, H. T1 - Innovative thin film techniques for microfabricating electrochemical sensors JF - Lecture Notes of the ICB Seminars Y1 - 2002 SP - 55 EP - 66 PB - MCB CY - Warsaw ER - TY - JOUR A1 - Schöning, Michael Josef T1 - Silicon-based biochemical sensors JF - CNI - The Center of Nanoelectronic Systems for Information Technology Y1 - 2003 SP - 165 EP - 170 PB - Foschungszentrum Jülich ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Lüth, H. T1 - Microfabricated semiconductor structures – Advances in (bio-)chemical sensing JF - Coupling of biological and electronic systems : proceedings of the 2nd Caesarium, Bonn, November 1 - 3, 2000 / Karl-Heinz Hoffmann, ed. Y1 - 2002 SN - 3-540-43699-5 SP - 79 EP - 92 PB - Springer CY - Berlin [u.a.] ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Schubert, Joachim P. A1 - Kloock, Joachim P. A1 - Zander, W. A1 - Mourzina, Y. G. A1 - Legin, A. A1 - Vlasov, Y. G. A1 - Lüth, H. T1 - Innovative thin film techniques for microfabricating electrochemical sensors JF - Biocybernetics and Biomedical Engineering. 21 (2001), H. 4 Y1 - 2001 SN - 0208-5216 SP - 107 EP - 119 ER - TY - JOUR A1 - Schroth, P. A1 - Weißbecker, B. A1 - Schütz, S. A1 - Ecken, H. A1 - Yoshinobu, T. A1 - Lüth, H. A1 - Schöning, Michael Josef T1 - Bioelectronic signal processing - intact chemoreceptors coupled to field-effect devices JF - Lecture Notes of the ICB Seminars Y1 - 2002 SP - 28 EP - 42 PB - MCB CY - Warsaw ER - TY - JOUR A1 - Schroth, P. A1 - Weißbecker, B. A1 - Schütz, S. A1 - Ecken, H. A1 - Yoshinobu, T. A1 - Lüth, H. A1 - Schöning, Michael Josef T1 - Bioelectronic signal processing - intact chemoreceptors coupled to field-effect devices JF - Biocybernetics and Biomedical Engineering. 21 (2001), H. 3 Y1 - 2001 SN - 0208-5216 SP - 27 EP - 42 ER - TY - JOUR A1 - Schöning, Michael Josef T1 - Novel approaches to design siliconbased field-effect sensors JF - Electrochemical Microsystem Technologies, New Trends in Electrochemistry Vol. 2 Y1 - 2002 SP - 384 EP - 408 PB - Taylor & Francis CY - London New York ER -