Research On Main Parts' Fatigue Of Large-scale Rotary Machinery With Multi-supporting

The large-scale rotary machinery with multi-supporting is the key equipment in the building material, metallurgy, chemistry. The fatigue of these main parts (such as shell, roller, wheel) of large-scale rotary machinery with multi-supporting is the primary reason which makes these large-scale rotary machinery go wrong or be in danger. It has great meaning for guiding main parts' design,production,test and management of the large-scale rotary machinery with multi-supporting to research on their fatigue.Aimed to the insufficiencies in existing fatigue prediction of the rotary machinery, the paper puts forward the method of combining fracture mechanics and local stress-strain theory to analyze the main parts' fatigue life according to their primary failure type, the main studying contents and conclusions are including:(1) Based on static finite element analysis of shell and fracture mechanics theory, the paper sets up the estimating model of shell's crack propagation life, acquires the relationship between its propagation life and the length of crack. Then, finds out some importance conclusions such as propagation of shell's crack roughly includes three stages: stable slow propagation stage, fast propagation stage and desirable propagation stage, the time of stable slow stage approximately composes 80% of the entire fatigue life and so on.(2) Based on contact finite element analysis of roller and wheel and local stress-strain method theory, the paper builds the estimating model of roller's crack initiation life, acquires the relationship between the roller fatigue initiation life and the axis line deflection. Then, educes some importance conclusions for example the contact stress is the main reason that leads to roller's outside fatigue failure; the axis line deflection has seriously influence to roller's initiation life, the reducing speed of life will be mild and so forth. (3) Based on contact finite element analysis of roller and wheel and fracture mechanics theory, the paper establishes the estimating model of the roller and wheels' crack propagation life, gets the relationship between their crack propagation life and the axis line deflection. Then, elicits some importance conclusions for instance the axis line deflection has seriously influence to their propagation life; the influence of axis line deflection to roller and the leaned wheel is consistent: the deflection becomes shorter, their propagation life become longer, and their speed are mild. But the other wheel is reverse, and its speed is rapid increase etc.