Determination of Stress Intensity Factors in Low Pressure Turbine Rotor Discs

Mathematical Problems in Engineering - Volume 2014 2014, Article ID 304638, 9 pages -

Research Article

Institute Gosa, Milana Rakica 35, Belgrade, Serbia

Military Technical Institute, Ratka Resanovica 1, Belgrade, Serbia

City of Belgrade Secretariat for Communal and Housing Affairs Office of Water Management, Kraljice Marije 1-XIII-XIV, 11000 Belgrade, Serbia

Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, Belgrade, Serbia

Received 3 October 2013; Revised 13 January 2014; Accepted 16 January 2014; Published 1 June 2014

Copyright © 2014 Ivana Vasovic et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

An attention in this paper is focused on the stress analysis and the determination of fracture mechanics parameters in low pressure LP turbine rotor discs and on developing analytic expressions for stress intensity factors at the critical location of LP steam turbine disc. Critical locations such as keyway and dovetail area experienced stress concentration leading to crack initiation. Major concerns for the power industry are determining the critical locations with one side and fracture mechanics parameters with the other side. For determination of the critical locations in LP turbine rotor disc conventional finite elements are used here. For this initial crack length and during crack growth it is necessary to determine SIFs. In fatigue crack growth process it is necessary to have analytic formulas for the stress intensity factor. To determine analytic formula for stress intensity factor SIF of cracked turbine rotor disc special singular finite elements are used. Using discrete values of SIFs which correspond to various crack lengths analytic formula of SIF in polynomial forms is derived here. For determination of SIF in this paper, combined -integral approach and singular finite elements are used. The interaction of mechanical and thermal effects was correlated in terms of the fracture toughness.

Author: Ivana Vasovic, Stevan Maksimovic, Katarina Maksimovic, Slobodan Stupar, Gordana Bakic, and Mirko Maksimovic

Source: https://www.hindawi.com/