@inproceedings{HuebelRudolphRotheretal., author = {H{\"u}bel, Hartwig and Rudolph, J{\"u}rgen and Rother, Klemens and Ziegler, Rainer and Willuweit, Adrian and Lang, Hermann and Deller, Simon}, title = {Performance Study of the Simplified Theory of Plastic Zones for the Fatigue Check}, series = {Proceedings of PVP2013, ASME 2013 Pressure Vessels and Piping Conference, Paris, 2013}, booktitle = {Proceedings of PVP2013, ASME 2013 Pressure Vessels and Piping Conference, Paris, 2013}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-5564-5}, doi = {10.1115/PVP2013-97137}, pages = {1 -- 9}, abstract = {As elastic-plastic fatigue analyses are still time consuming the simplified elastic-plastic analysis (e.g. ASME Section III, NB 3228.5, the French RCC-M code, paragraphs B 3234.3, B 3234.5 and B3234.6 and the German KTA rule 3201.2, paragraph 7.8.4) is often applied. Besides linearly elastic analyses and factorial plasticity correction (Ke-factors) direct methods are an option. In fact, calculation effort and accuracy of results are growing in the following graded scheme: a) linearly elastic analysis along with Ke correction, b) direct methods for the determination of stabilized elastic-plastic strain ranges and c) incremental elastic-plastic methods for the determination of stabilized elastic-plastic strain ranges. The paper concentrates on option b) by substantiating the practical applicability of the simplified theory of plastic zones STPZ (based on Zarka's method). Application relevant aspects are particularly addressed. Furthermore, the applicability of the STPZ for arbitrary load time histories in connection with an appropriate cycle counting method is discussed. Note, that the STPZ is applicable both for the determination of (fatigue relevant) elastic-plastic strain ranges and (ratcheting relevant) locally accumulated strains. This paper concentrates on the performance of the method in terms of the determination of elastic-plastic strain ranges and fatigue usage factors. The additional performance in terms of locally accumulated strains and ratcheting will be discussed in a future publication.}, language = {en} } @misc{HuebelWilluweitRudolphetal., author = {H{\"u}bel, Hartwig and Willuweit, Adrian and Rudolph, J{\"u}rgen and Ziegler, Rainer and Lang, Hermann and Rother, Klemens and Deller, Simon}, title = {Performance study of the simplified theory of plastic zones and the Twice-Yield method for the fatigue check}, series = {International Journal of Pressure Vessels and Piping}, journal = {International Journal of Pressure Vessels and Piping}, number = {116}, issn = {0308-0161}, doi = {doi:10.1016/j.ijpvp.2014.01.003}, pages = {10 -- 19}, abstract = {As elastic-plastic fatigue analyses are still time consuming the simplified elastic-plastic analysis (e.g. ASME Section III, NB 3228.5, the French RCC-M code, paragraphs B 3234.3, B 3234.5 and B3234.6 and the German KTA rule 3201.2, paragraph 7.8.4) is often applied. Besides linearly elastic analyses and factorial plasticity correction (Ke factors) direct methods are an option. In fact, calculation effort and accuracy of results are growing in the following graded scheme: a) linearly elastic analysis along with Ke correction, b) direct methods for the determination of stabilized elastic-plastic strain ranges and c) incremental elastic-plastic methods for the determination of stabilized elastic-plastic strain ranges. The paper concentrates on option b) by substantiating the practical applicability of the simplified theory of plastic zones STPZ (based on Zarka's method) and - for comparison - the established Twice-Yield method. The Twice-Yield method is explicitly addressed in ASME Code, Section VIII, Div. 2. Application relevant aspects are particularly addressed. Furthermore, the applicability of the STPZ for arbitrary load time histories in connection with an appropriate cycle counting method is discussed. Note, that the STPZ is applicable both for the determination of (fatigue relevant) elastic-plastic strain ranges and (ratcheting relevant) locally accumulated strains. This paper concentrates on the performance of the method in terms of the determination of elastic-plastic strain ranges and fatigue usage factors. The additional performance in terms of locally accumulated strains and ratcheting will be discussed in a future publication.}, language = {en} } @inproceedings{OpelNielsenBaueretal., author = {Opel, Matthias and Nielsen, Karl-Wilhelm and Bauer, Sebastian and Goennenwein, Sebastian T. B. and Gross, Rudolf and Cezar, Julio C. and Schmeißer, Dieter and Simon, J{\"u}rgen and Mader, Werner}, title = {Ferromagnetism and magnetic clusters in cobalt-doped ZnO}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 430}, abstract = {Ferromagnetic semiconductors (FMS) - i.e. semiconductors exhibiting long-range magnetic ordering - are intriguing materials. However, in spite of intensive research in the last decade, the existence of homogeneous FMS with a Curie temperature around or above room temperature still is controversial. A particularly tedious issue are local sample inhomogeneities or magnetic clusters, which can yield strong magnetic signals resembling the behaviour expected for a homogeneous FMS. Using pulsed laser deposition, we have grown cobalt-doped ZnO films on single crystalline ZnO substrates. Combining x-ray magnetic circular dichroism, DC magnetometry, and AC susceptibility measurements with a detailed structural analysis by high resolution x-ray diffraction, transmission electron microscopy, and electron-spectroscopic imaging, we can unambigously trace the characteristic, ferromagnetic-like behaviour of our ZnO:Co samples at room-temperature to nanometer-sized superparamagnetic metallic cobalt precipitates.}, language = {en} } @misc{OpelNielsenBaueretal., author = {Opel, Matthias and Nielsen, Karl-Wilhelm and Bauer, Sebastian and Goennenwein, Sebastian T. B. and Gross, Rudolf and Cezar, Julio C. and Schmeißer, Dieter and Simon, J{\"u}rgen and Mader, Werner}, title = {Nanosized superparamagnetic precipitates in cobalt-doped ZnO}, series = {The European Physical Journal : B}, volume = {63}, journal = {The European Physical Journal : B}, number = {4}, issn = {1434-6036}, pages = {437 -- 444}, language = {en} } @misc{MartienssenSchulzeSimon, author = {Martienssen, Marion and Schulze, Rolf and Simon, J{\"u}rgen}, title = {Verfahren zur Stabilisierung der Denitrifikation in biologischen Kl{\"a}ranlagen durch verbrauchte Kfz-K{\"u}hlerfl{\"u}ssigkeit}, language = {de} } @inproceedings{HuebelWilluweitRudolphetal., author = {H{\"u}bel, Hartwig and Willuweit, Adrian and Rudolph, J{\"u}rgen and Ziegler, Rainer and Lang, Hermann and Rother, Klemens and Deller, Simon}, title = {Performance study of the simplified theory of plastic zones and the Twice Yield method for the fatigue check}, series = {Proceedings of ANSYS Conference \& 31th CADFEM Users' Meeting, Mannheim, 2013}, booktitle = {Proceedings of ANSYS Conference \& 31th CADFEM Users' Meeting, Mannheim, 2013}, abstract = {As elastic-plastic fatigue analyses are still time consuming the simplified elastic-plastic analysis (e.g. ASME Section III, NB 3228.5, the French RCC-M code, paragraphs B 3234.3, B 3234.5 and B3234.6 and the German KTA rule 3201.2, paragraph 7.8.4) is often applied. Besides linearly elastic analyses and factorial plasticity correction (Ke-factors) direct methods are an option. In fact, calculation effort and accuracy of results are growing in the following graded scheme: a) linearly elastic analysis along with Ke correction, b) direct methods for the determination of stabilized elastic-plastic strain ranges and c) incremental elastic-plastic methods for the determination of stabilized elastic-plastic strain ranges. The paper concentrates on option b) by substantiating the practical applicability of the simplified theory of plastic zones STPZ (based on Zarka's method) and - for comparison - the established Twice Yield method. Application relevant aspects are particularly addressed. Furthermore, the applicability of the STPZ for arbitrary load time histories in connection with an appropriate cycle counting method is discussed. Note, that the STPZ is applicable both for the determination of (fatigue relevant) elastic-plastic strain ranges and (ratcheting relevant) locally accumulated strains. This paper concentrates on the performance of the method in terms of the determination of elastic-plastic strain ranges and fatigue usage factors. The additional performance in terms of locally accumulated strains and ratcheting will be discussed in a future publication.}, language = {en} }