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US 6,601,456 B1Granted
Fretting fixture for high-cycle fatigue test machines
AssigneeSouthwest Research Institute
InventorsDavid L. Davidson, Thomas E. Owen, John B. Campbell
Life of this patent
Estimating the term…
Abstract
A fretting fixture accessory for a_test machine (10) that induces high-cycle fatigue (at kilohertz vibration rates) in a specimen of a material under test. The fretting fixture (20) is clamped to the test specimen (21), for the purpose of testing for fretting damage. The fixture (20) is designed to provide both the normal and shearing forces that result in fretting damage.
Claims15
A fretting fixture for attachment to a specimen mounted in a fatigue testing machine, comprising:
- a clamping frame having at least two loading rods and two clamping beams, such that each loading rod extends through a clamping beam at each end;
- a pair of inertial masses inside said clamping frame, one adjacent to each clamping beam such that an air gap exists between opposing surfaces of the inertial masses within the frame;
- and
- a fretting contact piece attached to at least one of the opposing surfaces;
- the clamping frame operable to clamp the inertial masses to the specimen, one on each side of the specimen, with the fretting contact piece between one of the inertial masses and the specimen, such that the fretting fixture is supported by the specimen and moveable in space with the specimen.
2 more elements
A method of testing, for fretting stress, a specimen already mounted in a test machine, comprising the steps of:
- placing a fretting piece against the test specimen, the fretting piece having a contact area on a surface of the test specimen;
- clamping an inertial mass on each side of the combination of the test specimen and the fretting piece, thereby resulting in a fretting fixture assembly of the inertial masses clamped to the specimen, one on each side of the specimen, with the fretting contact piece between one of the inertial masses and the specimen, such that the fretting fixture is supported by the specimen and moveable in space with the specimen;
- and
- activating the test machine thereby causing the test specimen and fretting fixture to oscillate.
1 more element
Dependencies are inferred from the claim text.