000022017 001__ 22017
000022017 005__ 20170622131318.0
000022017 04107 $$aeng
000022017 046__ $$k2017-06-15
000022017 100__ $$aKapogiannis, Ioannis
000022017 24500 $$aPREDICTION OF RATCHET LIMIT UNDER THERMOMECHANICAL LOADINGS

000022017 24630 $$n6.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000022017 260__ $$bNational Technical University of Athens, 2017
000022017 506__ $$arestricted
000022017 520__ $$2eng$$aThe mechanical components of machineries, like nuclear reactors, aircraft gas turbine propulsion engines and piping systems, usually operate under high levels of cyclic thermo-mechanical loads. As a result of these loading conditions, the material usually exceeds the elastic regime, plastic strains occur and a final state appears, which may be either elastic shakedown (safe state), or plastic shakedown (unsafe state), or ratcheting (unsafe state). This state may be derived either using a time consuming step by step analysis or adopting modern Direct Methods. These methods are capable to estimate the limits of each cyclic state depending on the levels of the variable loads, without tracing the whole loading history. Towards this direction, the Residual Stress Decomposition Method for Shakedown (RSDM-S) has been developed, which can successfully predict the elastic shakedown limit [1]. In the present work, this method will be extended so that it may predict the ratchet limit. The method is formulated using three dimensional brick elements and is incorporated in FEAP [2]. It is assumed that a von Mises elastic perfectly plastic material holds. Finally applications of the approach to structures, subjected to combined cyclic thermo-mechanical loadings, are presented. ACKNOWLEDGEMENT This project has been financed by the State Scholarships Foundation (IKY), through the program “Research Projects for Excellence IKY/SIEMENS”. 

000022017 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000022017 653__ $$a

000022017 7112_ $$aCOMPDYN 2017 - 6th International Thematic Conference$$cRhodes Island (GR)$$d2017-06-15 / 2017-06-17$$gCOMPDYN2017
000022017 720__ $$aKapogiannis, Ioannis$$iSpiliopoulos, Konstantinos
000022017 8560_ $$ffischerc@itam.cas.cz
000022017 8564_ $$s117013$$uhttps://invenio.itam.cas.cz/record/22017/files/19889.pdf$$yOriginal version of the author's contribution as presented on CD, section: [MS33] WORKSHOP on Fragility Evaluation and Seismic Safety Assessment of “Special Risk” Industrial Plants (INDUSE-2-SAFETY)
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000022017 962__ $$r21500
000022017 980__ $$aPAPER