This paper presents the main assumptions and targets of the strain and stress states modelling of the steam turbine components. The analysis is undertaken due to the main components of HP and IP turbine sections (inner and outer casings, valve bodies and rotors) working under a significant load. Stress modelling has been divided into two parts: a simplified analysis and the detailed one. The former has been proposed in this way that the on-line calculations can be done. It’s based on special functions built upon multi-variant heat process simulations. The functions mentioned make it possible to describe the maximum component stress from some measured temperatures. This part should meet the requirements due to the stress state modelling during a usual turbine operation.
The detailed analysis comprises the unsteady operating conditions, bearing the stamp of intensive heating or cooling processes. As a result of the advanced calculation methods and full stress models being used the analyses is carried off-line.
