Fatigue Life Assessment of Hydro Turbine Shaft using Fem Crack Propagation Technique

Fatigue life assessment methods and hydro turbine shaft failure are studied in this paper. Failure (fracture) of a hydro turbine shaft is chosen as investigation topic. It basically emphases on fatigue analyses, taken after by fatigue life approximation of the element by means of fracture mechanics conceptions. Fracture mechanics can be used to analyze the advance of small flaws to critical dimensions by fatigue stacking and to estimate the fitness-for-service, or lifetime extension of present equipment. Linear elastic fracture mechanics (LEFM) is chosen as a theoretical process for calculating the fatigue lifespan of the notched element (hydro turbine shaft). LEFM gauges the fatigue lifecycle based on the information that a crack pre-exists in the element and that the fatigue lifecycle is directly depend on the stress intensity factor, which in-turn influenced by initial crack length.