Crack Paths 2012

N U M E R I CMAOL D EOLFT H ET U R B I NBEL A D E

It is necessary to clearly point out that all theoretical investigations of the turbine

blade behavior under thermo-mechanical fatigue were made for considerably higher

parameters than these in which blade works normally, i.e. about 800 0 C and 30000

rot/min.

Numeric study consisted of several stages:

- exact reproduction of thin ceramic layer in numerical model. The microscopic

examination was used to define the thickness of individual layers, Fig. 5. Generally

thermal protection structure of the turbine blade consists of: Bond Coat (BC), Thermally

GrownOxide (TGO)and Top Coat (TC),

Fig. 5. The structure of TBC.

- calculation of temperature distribution in one cycle of heating both for blade without

protective layer and with T B Ccoating,

- simulation of the thermo-mechanical fatigue behavior to define the number of cycles

leading to damage for different values of loadings.

Rys. 7. Segment of rotor.

Fig. 6. Single blade.

926