Effect of combined cycle fatigue on Ti6242 fatigue strength

✍ Scribed by L.Mendia; F.J. Estensoro; C. Mary; F. Vogel

• Publisher: Elsevier
• Year: 2011
• Tongue: English
• Weight: 268 KB
• Volume: 10
• Category: Article
• ISSN: 1877-7058
• DOI: 10.1016/j.proeng.2011.04.301

✦ Synopsis

Gas turbine blades are subjected to very high levels of stress and temperature during each engine operating cycle. Superimposed upon this quasy-steady state condition, blades also endure vibrational stresses induced by local perturbations. When characterizing advanced manufacturing candidate materials, conventional fatigue tests (low cycle and high cycle fatigue standard tests independently) fail to represent the complex set of stresses generated in gas turbine blades. Combined cycle fatigue (CCF) laboratory tests comprising LCF and HCF at service high temperatures have been completed on a titanium alloy used in intermediate pressure and high pressure compressor rotor and stator components. The aim of the study was to determine the influence of the combined damage mechanisms on the expected fatigue strength of gas turbine components. Standard test rigs have been modified in order to achieve this new and severe testing scenario. The effect CCF stresses was evaluated at a testing temperature of 350ºC. Results showed that the effect of superimposing LCF to HCF should be considered in blade design, especially at fillet radius.