Dynamics Analyze Of Straightening Roll System Of Short Steel Bar Straightening Machine

This article is studying a new type of automatic short alloy steel straightening machine,which can straightening a tool steel with 150 mm.The steel can be used to product the cutting tools which have a high straightness.A finite element model is established for the straightening rolls,and the straightening process is done in ANSYS/LS-DYNA.The simulation parameters is set up and the result of model quality scale is tested.In order to reflect the inherent characteristics of the straightening machine,a dynamic model of the roll system is established.At the condition of preloaded quantity in initiative rolls and displacement in press roll,the relative displacement of rolls is derived.Establishing dynamics differential equation and solving the equation,the nature frequency is obtained.Rolls' modal analysis is made in ANSYS Workbench,and the model frequency and main formation are obtained.The changing of model frequency is studied considering straightening rolls' thickness,press roll's diameter,press roll's thickness and straightening roll's diameter.Comparing the model frequency and nature frequency,which the rationality of calculate is tested by imitate.In order to reveal the nonlinear dynamic behavior of straightening rolls system,a dynamics model is built for the rolls' gap and dynamic load.The nonlinear dynamics differential equation is established,coordinate transformation of differential equations is worked,and the non-dimensional treatment is carried out.The differential equations is solved by the numerical analysis software,and the phase diagram and Poincare diagram are obtained.The parameter's influence on nonlinear dynamic characteristic is studied.The machine's stable is insured by changing the excitation number.