A rotor assembly for supporting rotor blades includes a plurality of axially adjoining discrete disks each having a rim. The rims include axial dovetail posts defining therebetween dovetail grooves for collectively supporting a respective blade dovetail therein. The disks are fixedly joined together by integral beams so that upon a crack failure of one of the disks, centrifugal load from the failed disk is transferred to an adjacent disk and crack propagation thereto is inhibited.