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examples-for-thermomechanical-loads
ThermBel1engl
Type of load:
Damage/
damage progress:
Examples
Temperature and stress progression:
1. Short-time loads
1.1 At constant
temperature
1.2 With sudden
temperature changes
("thermal shock")
- Plastic deformation
- Crack initiation
- Fracture
- "Runaway" turbines
- Explosions, containment incident
- Foreign object damage in a turbine
- Crack initiation during welding
- Crack initiation during quenching
- Schleifrissbildung
- Rubbing
- Bearing running hot
- Spark erosion
2. Creep loads
- Creep deformation
- Creep pore formation
- Crack initiation
- Fracture
- Turbine rotor blades
- Turbine stator blades
- Rotor disk (turbine, HP compressor)
- Housings (combustor, turbine)
- Rotors of turbines and HP compressors
- Housings (combustor, turbine, HPC)
- Bolts and tie rods (housings, rotors)
- Damage (structure)
- Creep deformation
- Creep pore formation
- Crack initiation with
cyclical crack growth
- Fracture
3. Loads in the LCF range
(< 10
4
LW)
3.1 Under the influence
of mechanical forces
3.2 Due to thermal stress
("thermal fatigue")
4. Loads in the HCF range
(>>10
4
LW)
- Damage
- Crack initiation with
cyclical crack growth
- Fracture
- Vibrating turbine blade
- Vibrating housing
- Dynamically stressed bolts and tie rods
- Vibrating labyrinths and shafts
- Turbine stator blades
- Annulus of an integral turbine disk
- Housings (combustor, turbine)
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T=f(t)
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t
t
T=f(t)
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Typical examples from the field of engine construction for
damages due to mechanical-thermal loads:
Welding Hardening Grinding