Abstract: According to many achievements in scientific research on steam turbines, some design criteria of the strength, vibration and life design of subcritical and supercritical steam turbine components are presented. The design criteria for the following 20 kinds of the design, including: static strength, finite element analysis of structures, diaphragm stiffness, stiffness of low pressure casings, differential expansion for steam turbines, vibrational strength for blades, vibrational strength for integrated shroud blades, flutter for long blades, vibration for first kind of tuned blades, vibration for second kind of tuned blades, vibraton for packet of blades on disk connected closedly, critical speed for rotor-bearing system, steadiness of oil whirling for rotor-bearing system, unbalance vibration response, torsional vibration frequencies for rotor-bearing system, torsional vibration strees for rotor-bearing system, steam-excited vibration, low cycle fatigue life, creep life and life under creep and low cycle fatigue interaction are given together with application range for the design criteria. With the design criteria as given, the safety and reliability of strength, vibration and life design of steam turbine components can be determined in the designing stage. The suggested method may provide a scientific basis for research, development and manufacture of large capacity steam turbines.

Key words: Design criterion, Life design, Reliability design, Steam turbine, Strength design, Vibration design, Axle box Bearings, Nonlinear Dynamics, Outer Ring Faults, High-speed EMUs