The area of cyclic stress-strain curve deviated from elastic line due to plastic deformation in the first cycle was taken as fatigue damage parameter

and the plastic strain energy-life model was established from the perspective of energy. With the method of quadratic interpolation for stress ratio

the relation of plastic strain energy and fatigue life under various stress ratios could be obtained. The testing results of the simulated bolt-hole specimens of a turbine disk and the simulated runway-hole specimens of an interstage disk were used for comparison and validation. Results show that the method of quadratic interpolation is more accurate compared with linear interpolation for stress ratio when using the plastic strain energy-life model. The calculated life of simulated bolt-hole specimen is 9.42% less than testing life; meanwhile the calculated life is just 1.88% larger than testing life for the runway-hole specimen. In general

the results of the plastic strain energy-life model fit well with testing life

showing a higher accuracy.