Fatigue test machine
Abstract
This invention relates to an apparatus for testing materials under combined static and dynamic loads. Materials used in rotating components of, for example, jet engines are subjected to unusually severe environmental conditions during their operational lifetimes. Components such as disks and blades are subjected to high temperature excursions, high levels of 'steady' stress from centrifugal loads (low cycle stress), as well as high levels of high frequency 'dynamic' stress from resonant vibration response (high cycle stress). The thermal-mechanical cycling of the component material can lead to initiation and propagation of cracks at voids, defects or scratches. The crack initiation and propagation characteristics of materials used in jet engine components vary widely, according to whether the material is more or less ductile, and depend on temperature, low cycle stress, high cycle stress, frequency, dwell time, local atmospheric conditions and many other parameters. This abstract discloses fatigue testing machine for testing materials under combined static and dynamic loads. The mach ine comprises a right circular ring, a pair of specimen clamps adapted for slidably fitting into diametrically opposed openings in the ring, a support cradle for the ring and a shaker. The clamps comprises means for applying a static load to a specimen clamped therebetween.
- Publication:
-
Patent Application Department of the Air Force
- Pub Date:
- December 1985
- Bibcode:
- 1985pad..rept.....J
- Keywords:
-
- Dynamic Loads;
- Fatigue Testing Machines;
- Hydraulic Equipment;
- Load Testing Machines;
- Static Loads;
- Vibration Simulators;
- Clamps;
- Cyclic Loads;
- Fatigue Tests;
- Patent Applications;
- Resonant Vibration;
- Shakers;
- Supports;
- Vibrational Stress;
- Instrumentation and Photography