The Experimental Study Of Hydraulic Bending Roll System's Effect On Plate Crown

Flatness, usually expressed in plate crown, is an important indicator in measuring the quality of plate strip product. As the most common and efficient means of flatness control, Hydraulic Bending Roll System has a direct effect on the quality of flatness. Many achievements have been made in the study of Hydraulic Bending Roll System's effect on plate crown. Yet, most of them were theoretical analysis and simulation, while further researches still need been made in systematic and experimental way. Therefore, combining theory with experiment, this thesis studies Hydraulic Bending Roll System's effect on plate crown systematically, providing solid evidences for improving the precision of plate strip steel products.This thesis classified the process of the research on Hydraulic Bending Roll System's effect on plate crown into two parts: one is Hydraulic Bending Roll System's identification; the other is theoretical calculation and experimental analyses on Hydraulic Bending Roll System's effect on plate crown.This thesis identified the input and output signals of Hydraulic Bending Roll System got from experiments by ARX identification method in MATLAB Identification Toolbox and State Space identification method respectively. Via comparing the two identification models, this thesis came to the conclusion that the model obtained by State Space identification method is more accurate. The accurate model derived from State Space identification method provides reference for analyzing and improving the control precision and affectability of Hydraulic Bending Roll System. However, identification method is not universal, and the identification model is only used for identified object. So identification method has some limitations. The model of bending force's effects on plate crown was established by the means of elastic foundation beam. On basis of that, this thesis got five groups of theoretical curves expressing bending force's effects on plate crown in five different conditions. Through experiments, this thesis got the data of bending force's effects on plate crown. Afterwards, this thesis obtained five groups of curves expressing bending force's actual effects on plate crown in five different conditions via processing and calculating the data. At last, by comparing and analyzing the group of curves of theoretical effects and those of actual effects, this thesis concluded the rule of Hydraulic Bending Roll System's effects toward plate crown.