DEVELOPMENT AND FUNDAMENTAL PERFORMANCE OF DUAL-SPINDLE ROTATING BENDING FATIGUE TESTING MACHINEWITH SPECIAL DEVICE PROVIDING CORROSIVE ENVIRONMENTS

Recently, particular attention has been paying to the fatigue property of metallic materials in the very high cycle regime and in corrosive environments from viewpoints to ensure the long term durability of mechanical structures and to realize the low-carbon sustainable society. Various kinds of mechanical structures have to be used in corrosive environments. In the mechanical design of such products, fatigue test data in the corresponding environment should be obtained as the fundamental design data. Conventional fatigue tests are conducted by setting the run-out number of loading cycles to N=10 7 , but the fatigue property in gigacycle regime is also focused as an important subject in recent years. In such a long life region, a tremendous long period is required to perform fatigue tests. In this study, a new type of dual-spindle rotating bending fatigue testing machine was developed in order to overcome these difficulties. By using this machine, one can perform the fatigue tests for four specimens simultaneously in rotating bending in the corrosive environment of 3% salt water. In this new type of machine, dual spindles are driven by an electric motor via V-belt and special technique was introduced in this additional facility in order to avoid the corrosive damage of the fatigue testing machine itself.