Abstract: A process for producing a small crack in a turbine rotor blade for use in training inspectors to be qualified for inspecting blades with small crack, where each blade is vibrated in order to initiate a small crack under observation using an IR camera that can detect for a small crack, and when a small crack at a desired size is produced on the blade, the vibration is stopped and the blade removed and then used in a training process to train and qualify an inspector for an inspection process.

Abstract: An apparatus and a process for determining the mass required for a wire damper ring to produce the maximum amount of damping in a certain rotary machine. The testing apparatus includes a test piece with an inward facing annular groove and a plurality of expander segments each with the top or outer half of a wire damper ring segment secured to and extending outward to fit within the annular groove. A mandrel with an outer surface having a slight slope is passed through a central opening of the expander segments and displaces the ring segments radially outward and into the annular groove at varying loads. The apparatus is set to vibrating and a piece of the test piece is observed for vibrations. The load applied to the damper ring segments is varied until the vibration is at a minimum. The applied load can now be correlated with the mass required for the damper ring to produce similar damping capability.

Abstract: The segments of the vanes of a stator and the blades of a rotor for a gas turbine engine are dampened by utilizing braided wire cable that is affixed to adjacent segments such that each of the wire strands forming the cable is allowed to move relative to each other to dissipate the vibratory energy inflicted on the stator or rotor. The ends of the cable are welded or heated and then tapered to facilitate fitting into a sleeve or collar which in turn is affixed to the adjacent segments by braze, weld or the like.

Abstract: A stack of piezoelectric crystals is placed on a shaft that is rotated to test a component on the shaft. An electrical signal is supplied to the stack, causing the crystals to vibrate, sending vibrations to the component as it spins. The component is enclosed in a vacuum chamber in order to provide a reduced pressure and thereby to reduce the power required to spin the component.