Tip-controlled integrally bladed rotor for gas turbine engine

A gas turbine engine including a fan, a compressor section, a combustor and a turbine section in serial flow communication and each defining an annular gas flow passage, the gas turbine engine comprising:

• at least one of the fan, the compressor section and the turbine section having at least one rotor, the rotor including a hub and a plurality of blades integrally formed therewith to define an integrally bladed rotor, the blades each extending radially outwardly from the hub to a remote blade tip and projecting into the annular gas flow passage of said at least one of the fan, the compressor section and the turbine section;
• a shroud circumferentially surround the rotor and having a radially inner surface adjacent to the blade tips, a radial distance between the inner surface of the shroud and the blade tips defining a tip clearance gap of the rotor;
• the hub of the rotor having a rim from which said blades radially project and a pair of axially opposed split hub members extending at least radially inward from said rim, each of the split hub members having a radially outer flex arm portion extending form the hub and a radially inner moment flange portion integrally formed with the flex arm portion, a radial inner edge of the moment flange portions defining a central bore of the rotor;
• and
• the rotor having at least one moment inducing element separately formed from the hub and mounted axially between the opposed split hub members, the moment inducing element acting on the moment flange portions of the opposed split hub members to generate an inward bending moment on the flex arm portions of the opposed split hub members during rotation of the rotor, thereby deflecting the rim and the blades of the rotor radially inwardly and minimizing the tip clearance gap between the blade tips and the shroud during operation of the gas turbine engine.