فاطمه قيطاسوند

The purpose of this research is to know the thermomechanical fatigue damage on the turbine and the effect of this damage on the turbine parts by entropy generation method. The components of the hot zone of a gas turbine, which includes the turbine section and the combustion chamber, are damaged under thermal and mechanical loads due to fatigue and creep mechanisms. Damage occurs in tandem, so it is necessary to consider their effects and the interaction of these two mechanisms together. In this research, fatigue and creep damage in the hot and cold parts of the turbine were first investigated. In the second part, the life eva‎luation methods in the field of fatigue and creep damage were investigated. These methods are divided into two categories: basic stress and basic strain. The basic stress methods are trying to create logical links between the stress applied to the part and its life, while the basic strain methods also use the strain parameter in this effort, and at the end, a new method for estimating the life of metal parts based on entropy production has been introduced. Related thermodynamic relationships and how to use entropy to estimate lifetime are mentioned in this section. In the third part, the basics of the research method and how to examine the damage through entropy are discussed according to the reference articles. The models expressed in the space of fatigue and creep damage failure mechanics can be used especially in the design with the presence of damage. Finally, taking into account the desired models, the final model was extracted and validated by Creep and USDFLD subroutines in Abaqus finite element software with reference articles, and after ensuring the accuracy of the model, the creep-fatigue life eva‎luation process for a sample The blade of the last stage of a low-pressure turbine has been subjected to thermomechanical loads, and according to the creep damage and fatigue caused, its life has been expressed as the number of operating hours, the number of times the turbine has been turned on, and the equivalent operating hours.

توربين گاز , آسيب , مكانيك خرابي آنتروپي , خستگي ترمومكانيكي

Gas turbine , Thermomechanical Fatigue , Damage, , Entropy Failure Mechanics

fatemeh gheytasvand

bijan mohammadi