Reliability-based combined high and low cycle fatigue analysis of turbine blade using adaptive least squares support vector machines

authored by
Juan Ma, Peng Yue, Wenyi Du, Changping Dai, Peter Wriggers
Abstract

In this work, a novel reliability approach for combined high and low cycle fatigue (CCF) estimation is developed by combining active learning strategy with least squares support vector machines (LS-SVM) (named as ALS-SVM) surrogate model to address the multi-resources uncertainties, including working loads, material properties and model itself. Initially, a new active learner function combining LS-SVM approach with Monte Carlo simulation (MCS) is presented to improve computational efficiency with fewer calls to the performance function. To consider the uncertainty of surrogate model at candidate sample points, the learning function employs k-fold cross validation method and introduces the predicted variance to sequentially select sampling. Following that, low cycle fatigue (LCF) loads and high cycle fatigue (HCF) loads are firstly estimated based on the training samples extracted from finite element (FE) simulations, and their simulated responses together with the sample points of model parameters in Coffin-Manson formula are selected as the MC samples to establish ALS-SVM model. In this analysis, the MC samples are substituted to predict the CCF reliability of turbine blades by using the built ALS-SVM model. Through the comparison of the two approaches, it is indicated that the reliability model by linear cumulative damage rule provides a non-conservative result compared with that by the proposed one. In addition, the results demonstrate that ALS-SVM is an effective analysis method holding high computational efficiency with small training samples to gain accurate fatigue reliability.

Organisation(s)
Institute of Continuum Mechanics
External Organisation(s)
Xihua University
Xidian University
Type
Article
Journal
Structural Engineering and Mechanics
Volume
83
Pages
293-304
No. of pages
12
ISSN
1225-4568
Publication date
10.08.2022
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Civil and Structural Engineering, Building and Construction, Mechanics of Materials, Mechanical Engineering
Electronic version(s)
https://doi.org/10.12989/sem.2022.83.3.293 (Access: Closed)
 

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