Patent ID: 7438532

Claim:
A method for reducing stress on at least one of a turbine disk and a turbine blade, wherein a plurality of turbine blades are attachable to the disk, and wherein each of the turbine blades includes a blade dovetail engageable in a correspondingly-shaped dovetail slot in the disk, the blade dovetail having a pressure side and a suction side, the method comprising: (a) determining a start point for a dovetail backcut relative to a datum line, the start point defining a length of the dovetail backcut along a dovetail axis; (b) determining a cut angle for the dovetail backcut; and (c) removing material from at least one of the blade dovetail or the disk dovetail slot according to the start point and the cut angle to form the dovetail backcut, wherein the staff point and the cut angle are optimized according to blade and disk geometry to maximize a balance between stress reduction on the disk, stress reduction on the blade, a useful life of the turbine blades, and maintaining or improving the aeromechanical behavior of the turbine blade, wherein the datum line is positioned 3.379 inches from a forward face of the blade dovetail along a centerline of the dovetail axis, and wherein step (a) is practiced such that for the pressure side of the dovetail, the start point of the dovetail backcut is at least 1.848 inches in a forward direction from the datum line.