Procedure:

The test stress is determined by selecting a percentage (%) of the tensile strength of the test material and converting that value into a bending moment. After the specimen is mounted into the machine collets, the speed control is adjusted to bring the machine up to the desired speed; the poise weight is then positioned on the calibrated beam to the bending moment previously calculated and locked into place. When the specimen fractures, the machine automatically stops and the number is recorded from the cycle counter (digital indicator up to 99,999,900). Specimens tested at various loads provide data for plotting a Stress vs. Number of cycles (S/N) curve. 

Equipment and Accessories:

To meet test needs of various applications, Fatigue Dynamics offers rotating beam test machines in bending moment capacities ranging from 60 in.-lb. to 1500 in.-lb. Optional accessories include a high temperature furnace (up to 1800°F), furnace temperature controller, and corrosion chamber.