A TOOL FOR THE STRUCTURAL INTEGRITY ASSESSMENT OF TURBINE DISKS: PROBABILISTIC AND NUMERICAL BACKGROUND

Rotor disks for gas turbines are heavy components and are usually designed following a safe-life approach, where the low-cycle fatigue analysis is carried out referring to design life curves with suitable probabilistic margins. However, in the case of such a heavy component there is the possibility of rare oc- currence of undetected defects or, better, the need to identify the defect acceptability for the different rotor regions (considering stress, temperature, mission profile). In order to carry out such calculations for a turbine ro- tor disk a software named AStrID (Assessment of the Structural Integrity of Disks) has been developed in close cooperation be- tween Politecnico di Milano and Ansaldo Energia (AEN). This paper summarizes its background and some of the relevant fea- tures.