Abstract
The authors carried out some fatigue tests under a set of program load which include peak load.
The conclusions are as follows:
(1) The effect of loading sequence on the fatigue life becomes greater, when the lowest stress level σ1 in program load becomes larger in this research.
(2) The value of Σ(n/N) sometimes becomes considerably smaller than unity when the lowest stress level σ1 is small.
(3) It appears that the understress that is lower than the endurance stress can reduce the fatigue life of the specimen in a program load.
(4) The increasing rate of horizontal deflection of the fatigue specimen is greater than that of vertical deflection, under the program load which include large stress.
