THREE-DIMENSIONAL MODEL BASED METHOD FOR PREDICTING CRITICAL VIBRATION SPEED OF SIX-ROLLER COLD ROLLING MILL

The present invention relates to the technical field of rolling process automation, and provides a three-dimensional model based method for predicting the critical vibration speed of a six-roller cold rolling mill. The critical vibration speed is predicted on the basis of a three-dimensional six-roller cold rolling mill model; considering that rollers should be regarded as short and thick beams and the effect of shear deformation needs to be considered, Timoshenko beams are selected, and Hermite interpolation is used for node displacement vectors; a vertical vibration kinetic equation of a rolling mill-rolled piece system may be created by analyzing the stress among a rolled piece, a roller, and a memorial archway and solved by using a Newmark-Beta method so as to obtain a roller displacement response curve at a specific speed; and if the amplitude of the displacement response curve is constant, the speed is the critical vibration speed of the rolling mill. According to the present invention, the effect of tw