Theoretical Studies And Engineering Application Of Shape Preset Control For HC Cold Mill Based On Strip Element Method

The shape control is the key technology and international leading problem of strip mill. At present, the theory and mathematical model of shape control can not adapt to the demands of shape control technology developing. Determination of the shape control scheme is dependent on large amount of producti3n test and accumulation of experience, and lacks of the mature theoretically scheme and mathematical model. Three-dimensional flat rolling theory based on strip element method and shape control strategy and preset control model for HC strip mill is selected as researching object in this dissertation, closely theoretical study and engineering application is carried out. The third power spline function streamline strip element method is formed, which makes third power spline function fitted exit lateral displacement on the basis of the streamline strip element method. In this theory, lateral displacement is continuous in all deformation zones, and is satisfied with the compatibility conditions of the first-order and second-order derivative of exit lateral displacement on element nodes. The number of strip elements is largely reduced, and the computing speed is raised when this theory is employed. The exact model of front tension stress transverse distribution is established on the basis of analysize the shortcomings of existing tension stress transverse distribution model. Applying the new model to third power spline function streamline strip element method, the numerical analysis of three-dimensional deformation of cold rolled strip is carried out, which obviously improves dependence of the calculation results?convergence on initial value. Calculating model of strip flatness and profile for the 900mm HC cold rolling strip mill is built up by combining rolls system deformation calculation and metal deformation model. The calculation results on strip front tension stress and profile are well agreed with experimental results for industry cold rolling strip. This verifies that the theory model is reliable. Introducing the technology of artificial network into the system of shape control, and the shape pattern recognition model is established with the neural network of error back program (EBP), the defects of traditional shape pattern recognition based on the method of minimum squares is overcomed. The more practical and simple distinguishing model, of the rolled strip's stabilization is set up with energy method that depends on small- deflection elastic theory. The total analytical model of HC mill shape and control is presented based on the 3-dimentional plastic deformation model of strip, the rolls deformation model, distinguish model of stabilization and the shape pattern recognition model of rolled strip. A suite of emulation software including the whole shape control and analysis software and the figure show software is programmed. The shape control special properties of HC mill is studied and the shape control tactics of the mill is determined by means of numerical emulating the shape control of the mill with the software, therefore the mathematical model of shape control of the HC mill is established. Industrial test of shape preset control for cold rolled strip is finished on 900mm HC rolling mill of Hengshui sheet Inc. of Handan Iron and Steel Corp. The correct shape preset control model is provided for major rolling specifications of the mill after testing and verifying the analysis result's correctness of the emulation software. The test results...