Experimental and numerical study based on ductile failure for the tri-hub burst of turbocharger turbine

Abstract

The prediction of the tri-hub burst of turbocharger turbine at a given speed range is a current problem of great practical interest. In this work, the theory of rotating discs burst is used to guide the design of pre-weakened turbine scheme, and a ductile failure approach, namely a coupled plasticity-damage model, is employed to predict the tri-hub burst of the pre-weaken turbine. The optimal defect sizes are obtained by burst simulation using the coupled plasticity-damage material model. Two pre-weakened turbine specimens is conducted in turbine containment test bench. Experimental results show that the tri-hub burst view between the simulation and experiment have a good agreement. For two pre-weakened turbine specimens, the burst speed error of simulation and experiment are 0.5% and 3.1%. Comparison with the prediction of the burst speed by the theory of linear elastic model and the theory of elastoplasticity, the burst speed predicted by the former is much less than the target burst speed (270,000 r/min), while the burst speed predicted by the latter is much larger than the target burst speed. In conclusion, the ductile failure approach is presented in the tri-hub burst prediction of the turbine to show that it is more accurate to predict the target burst speed. In addition, it also prove that the rotating discs burst theory can be used to guide the design of pre-weakened turbine scheme.