Abstract: Aiming at the safety of steam turbine and the whole power plant, the research on the reliability analysis of steam turbine blade was conducted. By taking a lowpressure steam turbine blade as an example, the distribution types of random variables such as blade material, rotational speed and steam flow rate were determined firstly; Meanwhile, deterministic finite element method, response surface method and MonteCarlo simulation method were combined to determine the reliability indexes. The probabilistic sensitivity of random parameters to static strength and vibration was also discussed. The results indicate that the reliability indexes of static strength, dynamic strength and vibration are 1.0,0.98,1.0 respectively. When both strength and vibration failure modes are considered, the reliability index R=0.98, which failed to meet the requirement of 99.73% (±3σ criterion). The sensitivity results of reliability show that the density of material has the strongest influence on static strength and vibration, therefore, the density of materials should be strictly controlled.
Key words: reliability; response surface; probability sensitivity; MonteCarlo simulation