Turbine Blade Life EstimationThe blade life estimation is a multifaceted technology, involving free and forced vibration forces, that lead to the determination of steady and dynamic stresses at different critical speeds during the startup and shutdown procedures, as well as in the operational speed range. Propagation and unstable fracture are described with practical examples to estimate blade life. |
Contents
Low Cycle Fatigue Life Estimation by Stress Based Theories | 52 |
High Cycle Fatigue Life Estimation by Stress Based Theories | 86 |
Finite Element Analysis of Blades | 209 |
Local Stress Strain Approach for Crack Initiation | 237 |
Linear Elastic Fracture Mechanics | 268 |
Determination of Stress Intensity Factor from Compliance | 296 |
Stress Intensity Factor Approach for Fatigue Crack Initiation | 308 |
8 | 320 |
Common terms and phrases
aerodynamic airfoil alternating stress ASTM bending camber chord circulation coefficient component crack growth crack initiation crack length crack propagation crack tip critical speeds cycle fatigue Cyclic damage damping ratio determine displacement distribution dynamic stresses elastic endurance limit equation estimation excitation forces Fatigue Crack fatigue limit fatigue strength flow Fracture Mechanics fracture toughness function gear given HARMONIC K₁ linear machine material MEAN STRESS DUE mode shapes N/mm natural frequencies notch number of cycles obtained parameter plane strain plastic zone radius ratio rotor rotor blades S-N curve S-N diagram S₁ shown in Fig specimen stage stator blade steady forces STEADY LOAD steels stress amplitude stress concentration stress concentration factor stress intensity factor stress level stress range torque trailing edge turbine blade turbomachine unsteady lift velocity vibration viscous damping Von Mises stress vortex vorticity yield strength ΔΚ