Research On Torsional And Vertical Vibration Characteristics Of Six-high Cold Rolling Mill

With the intensity of market competition and the improvement of demand of downstreamindustries on the quality of steel products, the higher requirements on the quality and appearanceof strip steel surface are also put forward. Vibration of cold rolling mill will directly affectquality and aesthetics of strip steel surface, so how to eliminate vibration of the cold rolling millbecome a problem that must be solved. The vibration of cold rolling mill is generally dividedinto two parts, one part is the torsional vibration of the main drive system of cold rolling mill,another part is the vertical vibration of cold rolling mill stand. Torsional vibration will result inthe destruction of the main drive system and impact production. Vertical vibration will causethickness different of strip steel surface and color differences of strip steel surface, which willaffect the surface quality of strip steel. So the studies on vibration characteristics of cold rollingmill have particular theoretical and pragmatic meaning.Studies on vibration characteristics of cold rolling mill were carried out from the followingaspects.(1) A study of torsional vibration of the main drive system of cold rolling mill. According tothe related theory of mechanical vibration, the model of the main drive system of cold rollingmill was simplified. Mathematical model of torsional vibration of the main drive system wasestablished, and each order natural frequency and the formation matrix were calculated out byMATLAB programming, then torque amplitude factor was solved, and the changing curve oftorque amplitude factor with related parameters was drawn up. According to these, the methodsof reducing torque zoom coefficient and optimizing universal spindle were put forward.(2) A study of vertical vibration of the cold rolling mill stand. The models of the cold rollingmill stand and various parts were established by Pro/E, modal analysis of these models wasproceed by ANSYS. According to the result of analysis, the frequency which causes the verticalvibration of rolling mill stand was found out.(3) Dynamic Simulation and Analysis of rolling process of cold rolling mill were proceed.The model of roll system was created and analyzed by ANSYS/LS-DYNA. The displacementdiagrams of the roll node were drawn with LS-PrePost. The dynamic characteristics of thedifferent rolling speeds and thickness were comparative analyzed and spectral analysis of nodaldisplacements of working roll and strip surface was carried out by MATLAB programming.Measures of reducing vibration and improving the rolling accuracy were pertinently put forward.