Turbine Disc Fracture.pdf

The study focuses on the fracture mechanics analysis of damaged turbine rotor discs using the finite element method. The analysis evaluates fracture mechanics parameters in low-pressure turbine components, specifically at critical locations such as keyway and dovetail areas. The J-Integral approach is used to calculate stress intensity factors, which are essential in predicting crack initiation and propagation. The study aims to develop analytic expressions for stress intensity factors at critical locations of low-pressure steam turbine discs.

The finite element method is used to determine the critical location, zone of stress concentration, and crack propagation in the turbine disc. Various crack lengths are assumed, and stress intensity factors are determined under thermomechanical loads. The study also investigates the effect of temperature on material properties and the resulting stress intensity factors.

The results provide valuable data for predicting the service life of turbine discs and understanding crack growth behavior. The study combines the finite element method with the modified J-integral approach to analyze thermomechanical problems related to fracture mechanics. The analysis is validated through numerical simulations, and the results are presented in the form of stress intensity factors for different crack lengths and temperatures.

Key findings include:

The stress intensity factor is a critical parameter in predicting crack initiation and propagation in turbine discs.
The finite element method and J-Integral approach can be used to evaluate fracture mechanics parameters in low-pressure turbine components.
Temperature has a significant effect on material properties and resulting stress intensity factors.
The study provides analytic expressions for stress intensity factors at critical locations of low-pressure steam turbine discs.

The research has implications for the design and maintenance of turbine discs, highlighting the importance of considering fracture mechanics and thermomechanical loads in the analysis of rotating components.