Study On Frame Fatigue Experiment Of800MN Die Forging Hydraulic Press

800MN large die forging hydraulic press using plate combined precompressiontype rack. As one of the main components of the machine, rack is under heavy load.The strength, rigidity and reliability of the entire machine is working correctly. Theframe strength and stiffness under the static loading has been much studied. But thefatigue damage under cyclic loading has not been reported. It is statistical that about50~90destroy of the engineering structure and mechanical equipment is fatiguedamage.By the large finite element analysis software MSC.Marc, the paper established the3D finite element model of800MN die forging hydraulic press, Rack in the state ofstatic load and cyclic loading prone to fatigue crack dangerous points.Taking800MN die forging hydraulic press machine frame as the prototype, thetest model is designed according to the proportion of1:30,conducted the static loadtest and the fatigue life test. Through the static load test to judge the stability of theworking state of the frame and the accuracy of the data. By the size of the data valuesto judge whether there is yield, according to the variation of data before and afterloading to determine the positions of dangerous points of the frame and stress valuessituation, and the change of stress of the drawbars after loading: Through the dynamicload cycle experiment to monitor the stress and strain condition of each dangerouspoint and the change of pre-tightening force of the drawbars. Verify in the sameworking load, the influence of different pre-tightening force on the changes ofdangerous points of the frame and the stress and strain of dangerous points, whetherthere is pre-tightening relaxation phenomenon on the drawbars to evaluate thereliability of the structure: Through accelerated life test to determine the dangerouspoints of the static load test whether to change in the process of dynamic load cyclesand after how many times the dangerous points occur to yield, and determine thefatigue life of the frame. Provide the basis for the reliability design of800MN die forging hydraulic press machine.