STRESS-STRAIN STATE PREDICTION OF HIGH-TEMPERATURE TURBINE SINGLE CRYSTAL BLADES USING DEVELOPED PLASTICITY AND CREEP MODELS

摘要

This paper discusses a novel approach to calculating inelastic strain that incorporates elastic anisotropy in combination with ANSYS finite element analysis (FEA) software to predict the stress-strain state kinetics of a single crystal (SX) nickel-based turbine blade. The approach is based on using "equivalent direction" and allows us to correctly define the critical load value and plastic strain field in SX details for different load types. The suggested approach is simple and generic and requires only a few standard experimental material properties. This should allow for an easy transition to actual blade design application. Predictions of plastic field distribution obtained using the suggested approach with anisotropic specimens are compared with experimental data as well as with the results obtained using a crystallographic approach. Good correlation was achieved. The second goal of this study is to develop a physically based, readily implementable creep model SX superalloy that accurately represents the creep phenomena of these materials under complex, thermomechanical loading conditions.