A series of fatigue tests were made on high pre-stressed notched specimens. A specimen was stretched statically, and thereafter fatigue load (completely reversed axial stress, pulsating tensile stress or rotating bending stress) was applied on it.
The schedule of experiments are shown in Table I.
The fatigue test results show that when a considerably high pre-stress is applied on a notched specimen, the specimen is possible of improvement in fatigue strength, but the extent of the improvement will be influenced by the kind of material, the shape and size of the notch, and the extent of pre-stress.