A Newly Devised Resonance Type Rotating Bending Fatigue Testing Machine and Some Fatigue Tests

Abstract

A new rotating bending fatigue testing machine which operates in a perfectly resonant condition under a new principle has been devised and constructed. The specimen is subjected to a rotating bending stress by the inertia force of an eccentric mass forcibly rotated, although the specimen is fixed to the frame of the machine and can't rotate. The amplitude of the vibration can be arbitrarily varied from zero to a maximum by the movable drive shaft which is especially devised, so that the starting of the test and the regulation of the amplitude are easy and exact. when the driving speed attains the resonance point, the motion of the inertia mass becomes exactly circular. Some fatigue tests were carried out on smooth and notched specimens, and the machine proved to be satisfactory in operation.