Fatigue life prediction of turbine blades with geometric imperfections made of stainless steel

This research addresses critical challenges faced by steam turbine blades, particularly in low-pressure (LP) turbines, where premature failures are common due to stress concentrations at the blade root area. The study introduces a numerical methodology aimed at predicting the life of mistuned steam...

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Bibliographic Details
Main Authors: Makgwantsha Hermelton Mashiachidi, Dawood A. Desai
Format: Article
Language:English
Published: Balkan Scientific Centre 2023-12-01
Series:Tribology and Materials
Subjects:
Online Access:https://www.tribomat.net/archive/2023/2023-04/TM-2023-04-03.pdf
Description
Summary:This research addresses critical challenges faced by steam turbine blades, particularly in low-pressure (LP) turbines, where premature failures are common due to stress concentrations at the blade root area. The study introduces a numerical methodology aimed at predicting the life of mistuned steam turbine blades, with a focus on variations in blade geometry which have received limited exploration in existing literature. A simplified, scaled-down mistuned steam turbine bladed disc model was developed using Abaqus finite element software. Acquisition of steady-state stress response of the disc models was performed through finite element analysis (FEA). Thereafter, numerical stress distributions were obtained. Subsequently, within Companion software, a Monte Carlo simulation-based probabilistic approach was applied to evaluate and quantify uncertainties in fatigue life for 17 cases. This analysis considered an accepted manufacturing percentage scatter of ± 5 % for the steam turbine bladed disc. That was conducted by selecting mistuning (geometry variation) percentages as the random variables. The methodology demonstrated reliability, correlating well with literature-based and discrete fatigue life results. This study establishes the potential for accurately predicting the fatigue life of mistuned steam turbine blades using the developed methodology.
ISSN:2812-9717