A Flexural Fatigue Machine for High-Temperature Operation at Resonance in Vacuum

摘要

A resonance type reversed-bending, high-temperature fatigue machine for operation at constant bending amplitude in vacuum has been developed. The vibration frequency is maintained at resonance by means of a feedback circuit employing a capacitance pickup. Another circuit maintains a constant amplitude of vibration. As fatigue cracks are developed, the resonant frequency is reduced. Curves of resonant frequency versus time at 800C for materials of high damping, such as Type 316 stainless steel, and for materials of low damping, such as Inconel X, illustrate the development of fatigue damage. (Author)