Turbomachine rotor assembly having reduced stress concentrations

摘要

A method and apparatus for reducing stress concentrations in a turbomachine rotor assembly are disclosed. A layer of superplastic metal is applied to a bearing surface formed on the turbine blade root. After assembly of the turbine blade to the rotor disk, the blade is pre-loaded to bring the superplastic metal layer into contact with adjoining bearing surfaces formed in the rotor disk groove. The superplastic metal material is capable of plastically deforming at least 500% thereby conforming to substantially all of the variations between the bearing surface formed on the blade root and the corresponding bearing surface formed on the rotor disk groove. By maximizing the contact area between the bearing surfaces, the stress concentrations are reduced.