Session: 26-02 Probabilistic Fatigue Crack Nucleation and Growth Lifing Applications

Paper Number: 153277

The IBESS Model As a Base for Probabilistic Modeling of Fatigue Life Prediction in Cast MAR-M247 Considering Shrinkage Pores 

Malek Al-Ameri^1,*, Christian Amann¹, Jan Radners², Christoph Schweizer², Michael Schlesinger²,
Stefan Eckmann², Peter Gumbsch^2,3, Kai Kadau⁴

¹ Siemens Energy Global GmbH & Co. KG, Mülheim a. d. R., Germany
² Fraunhofer IWM, Freiburg, Germany
³ Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Karlsruhe, Germany
⁴ Siemens Energy Inc., Charlotte, NC

A gas turbine (GT) operating in a renewable-integrated grid is subjected to repeated start-stop cycles and quick load ramps. Such conditions highlight a risk of potential increase of cyclic damage in its critical rotating components such as turbine blades. A multiyear government-funded project is in progress to evaluate the low cycle fatigue (LCF) behavior of a cast blade material with defects to develop a probabilistic fatigue life model. This paper is the third in a continuum of publications [1, 2]. To consider a deterministic model that serves as a base for the proposed probabilistic framework, this work investigated the use of the so-called IBESS-modified NASGRO equation [3]. Key fatigue and fracture mechanics concepts are briefly reviewed for a better understanding, followed by a detailed description of the IBESS modification. LCF tests were conducted on defective and defect-free flat and round specimens extracted from cast MAR-M247 GT blades. The model was applied using the data generated from the strain-controlled LCF tests. While the model predictions overestimated the number of cycles to crack initiation for most specimens, it showed promise for further improvements. Future work is expected to define a more accurate failure criterion and to achieve better corrections for crack and specimen size and geometry.

Presenting Author: Malek Al-Ameri Siemens Energy Global GmbH & Co. KG

Presenting Author Biography: Mar 2022 - Present:
Siemens Energy - Doctoral Candidate

May 2021 - Nov 2021:
Tata Steel in Europe - Master Thesis Intern

Sep 2019 - 2021:
Luleå University of Technology - M.Sc. in Materials Engineering

Jun 2017 - Dec 2017:
Lehigh University - Exchange Program, Mechanical Engineering

Aug 2014 - May 2019:
King Fahd University of Petroleum & Minerals - B.Sc. in Mechanical Engineering

Authors:

Malek Al-Ameri Siemens Energy Global GmbH & Co. KG
Christian Amann Siemens Energy Global GmbH & Co. KG
Jan Radners Fraunhofer Institute for Mechanics of Materials IWM
Christoph Schweizer Fraunhofer Institute for Mechanics of Materials IWM
Michael Schlesinger Fraunhofer Institute for Mechanics of Materials IWM
Stefan Eckmann Fraunhofer Institute for Mechanics of Materials IWM
Peter Gumbsch Fraunhofer Institute for Mechanics of Materials IWM
Kai Kadau Siemens Energy Inc.