Strength Analysis And Life Prediction Of A Turboprop Gas Turbine Rotor

Research on strength and fatigue life of a turboprop gas turbine rotor is done in this paper. The finite element models of three turbine disks and six turbine blades of this engine is built by commercial FEA software, and finite element stress analysis of the turbine discs and blades is performed. Centrifugal loading and thermal loading due to non-uniform temperature field are considered in the stress analysis. The results indicate that the maximum stress point of three stage turbine discs locate at the eccentric hole, three stage turbine discs meet the require of the strength design. Three stage turbine blades also meet the requirement of the strength design. The effect of the size of fillet on the maximum stress of joints of the blade is studied in this paper. The curves related the radius of the fillet and the maximum stress are plotted. The contact stress between the turbine tenon and dovetail slot is analyzed. The maximum stress of the second and third stage turbine dovetail slot exceeds the yield stress of the material. The EGD-3 Stress Standard is applied to calculate the turbine rotor fatigue life. The results indicate that the eccentric hole of the second stage turbine disc has the shortest fatigue life, but the cycles are more than2×10~4 ; The fatigue cycles of the eccentric hole of the first and third stage turbine disc are both more than 10~5. The cycles of the three stage turbine blades are all more than 2×10~5. The cycles of all the turbine tenons and dovetail are more than 2×10~4 except the second stage turbine tenon, is 10~4.