Research On Nonlinear Primary Parameter Resonance In Cold Rolling Process

The rolling mill take on heavy responsibilities that production of nearly 1 billion tons of steel in china.It's heavy-duty,high-speed and high-precision properties have received widespread engineering circles coverage,Scientific research personnel have obtained many research results on vibration mechanism and vibration control.Nevertheless,Rolling mill equipment as a complex mechanical,Constantly highlighting nonlinear vibration phenomena in actual production process,For instance,Due to chatter has becom a long-term problem of rolling mill working,Therefore the production capacity of rolling mill equipment has been greatly reduced.The non-linear vibration phenomenon of cold-rolled strip in rolling process is an indispensable part of the research on rolling system vibration.In this dissertation,Deriving the vibration governing equation of cold rolled strip based on the elastic theory and Hamiltonian principle.In addition,The dimensionless form of the vibration governing equation is given.The vibration governing equation is discretized by Galerkin method,And the natural angular frequency and attenuation coefficient of the fourth mode of the moving strip are solved by eigenvalue method.The parametric vibration equation of cold rolled strip is solved,After using the Poincare-Lindstedt method,Besides,the stability diagram of parametric vibration in the rolling process is given.Not only the vibration forms of the strip in the stable and unstable regions are analyzed,But also explains the main parametric resonance phenomenon of cold rolled strip.In order to solve nonlinear parametric vibration equation,This paper uses improved multi-scale method and Runge-Kutta algorithm.After the calculation,Discusses the effects of important rolling process parameters such as rolling speed,strip thickness,continuous rolling tension,and roll angular velocity fluctuation rate on the resonance characteristics of the main parameters of cold rolled strip separately.It has engineering application significance for finding ways to suppress the nonlinear vibration of rolling mills,improving the quality of cold-rolled strips,and optimizing rolling processes.