Session: DA-03-02 Fatigue-2

Paper Number: 153381

153381 - Fatigue Testing and Lifetime Assessment of Components Under Variable Amplitude Loading in Operation Conditions 

Abstract: 

The fatigue assessment of nuclear reactor internals and piping is of high importance with regard to safety, reliability and longterm operation of nuclear power plants. Due to their excellent mechanical and technological properties as well as their corrosion resistance austenitic stainless steels are often used for reactor internals and piping systems. These are subject to mechanical and thermo-mechanical loading in all fatigue regimes (Low Cycle, High Cycle and even Very High Cycle Fatigue). For this purpose, numerical simulations of thermo-mechanically loaded components with focus on their welded joints as fatigue relevant locations are conducted. With special regard to the toes of weld joints the multiaxiality is investigated by means of advanced strain- and energy-based fatigue damage parameters. A multilinear kinematic elastic plastic material model is used in connection with experimental data of the investigated materials. In addition, fatigue testing of the Control Rod Guide Assembly Support (CRGAS) component and pipes is conducted in order to further validate the methods of multiaxial fatigue life assessment under operating conditions of nuclear power plants. The applied variable amplitude loading resembles loads measured in real operational components.  With the presented work the design guidelines can be further improved by comparing experimental fatigue lifetime with analytical fatigue lifetime assessment.

Presenting Author: Georg Veile Materials Testing Institute Stuttgart

Presenting Author Biography: After studying aero and space technology and working as student in the aero- and space industry, as well as automotive R&D, I decided to commit to a PhD about fatigue design. At MPA Stuttgart I have the opportunity to research the fatigue behavior of austenitic stainless steels in corrosive environments. Furthermore, the fatigue assessment of components and their welds plays a significant role in the research project “VHCF Austenit II”, where we aim to improve fatigue life prediction in LCF, HCF and VHCF.

Authors:

Georg Veile Materials Testing Institute Stuttgart
Nina Grözinger Materials Testing Institute Stuttgart
Jürgen Rudolph Framatome GmbH
Udo Fischer Framatome GmbH
Stefan Weihe Materials Testing Institute Stuttgart