Reliability evaluation method for turbocharger turbine with overspeed failure mode

For the turbine with failure mode of overspeed, the effect of the number of blades and load application on the reliability of turbine is studied, and the reliability and failure rate models of turbocharger turbine under ultimate load are developed. First, the structural characteristic of turbine is analyzed, and the probability distribution function of strength of turbine capable of reflecting the effect of the number of blades, is derived. For the failure mode caused by the ultimate load of overspeed, the models of reliability and failure rate of turbine are developed, respectively, which can embody the effect of the number of blades, load, strength and the operating cycles. Taking a turbocharger as an example, the behavior of the reliability and failure rate of turbine changing as the number of operating cycles is studied. The results show that as the number of operating cycle increases, the reliability of turbine decreases and the failure rate also decreases. The models proposed in this paper can be applied to analyze and evaluate the reliability of turbine more scientifically.