Estimation of Creep and Cyclic Damage Accumulation in Micro-Turbine Disc

Abstract

The micro-turbine unit is intended to provide 100 kW of electric supply. The turbine is small size (turbine wheel diameter 150 mm), high speed (65,000 rpm), and should have big enough durability (60,000 hours). Creep in stationary regime and cyclic inelastic deformation due thermal stresses at start up and stop restricts the turbine lifetime. Numerical analysis of temperatures, the creep strains and cyclic strain range shows that points with maximum creep damage and cyclic damage are different. This fact allows estimating the structure lifetime without exact knowledge of summation rule for the damages.