Contact stress analysis and fatigue life prediction of turbine disc–blade attachment with fir‐tree tenon structure
Rong Yuan, Ding Liao, Shun‐Peng Zhu, Zheng‐Yong Yu, José A.F.O. Correia, Abílio M.P. De Jesus
Abstract
Abstract Fir‐tree tenon structure, as a commonly used scheme in the connection of turbine blades and discs, plays a critical role in the reliability and integrity of aeroengine turbines. This work mainly deals with the contact and fatigue analyses of a turbine disc–blade attachment with fir‐tree tenon structure. Firstly, based on Hertz contact theory, a three‐dimensional (3D) model of surface‐to‐surface contact is established, and contact stress analysis is performed based on finite element (FE) simulations. The simulated contact stress distribution agrees well with the Hertz contact theory. Particularly, the rounding processing does not relieve the stress concentration. Then, contact stress analysis on the fir‐tree tenon structure is performed, and a stress gradient‐based model is utilized for fatigue life evaluation together with contact stress analysis. Results show that the proposed solution yields acceptable predictions compared with field estimations.