Large-scale Rotary Kiln Components Rolling Contact Stress Field And Fatigue Life

Rotary kiln is the key equipment in metallurgy, chemistry and architectural material. So the safety and efficiency of its operation is the crux to advance economic benefit of such enterprises. Rotary kiln's main supporting part, the roller and pad, are working in the style of rolling contact. For a long time, people don't know the stress on the surface of roller when rotary kiln is hot. The main invalidation of the supporting system is fatigue flaking and crack of roller, the fatigue break of the axis of roller. On worse, the sudden fails of them can be a great threaten to workers' lives on the operating bridge, and what's more, it will cause the break of the production process, hence great productivity losses.To the problem, the stress in contact field between roller and pad in rolling contact state has been studied. The stress component's calculating formula on contact surfaces and internal contact zone of rotary contact component in a state of traction rolling contact have been deduced, and the contact component's axes are parallel.Based on it, the maximum primary shearing stress's value, position and direction have been analyzed, the fretting fatigue pits' crack propagation path has been determined. Many local pictures and other scholars' studies have been carried out and conclusions about the correctness of the crack propagation path, it also proved that the fretting fatigue pits' crack propagation is governed by mode II loading and crack path is controlled by the maximum primary shearing stress at the advancing crack tip.The fatigue load spectrum at risk spot on roller's surface has been made by the stress component's calculating formula and the analytic result of engineering software ANSYS, then the fretting fatigue pits' crack initiation life has been calculated by Stress and Strain Analysis.On the basis of the famous Paris formula, the fretting fatigue pit's life has been calculated by a new algorithm, which is about prediction of fatigue crack propagation life and achieved by MATLAB program. The effect on fretting fatigue pit's life brought on by friction coefficient has been researched.