Application Of Improved Rotative Mid-point Mensuration And Newton Method In Flat Rolling

Finite element method (FEM) has been widely applied to strip rolling process. At present, heightening the calculating efficienc of FEM with ensuring calculating precision has been the key issue in solving problems of on-line application. Many numerical methods such as Newton method have been employed to solve the system of simultaneous equations obtained in FE and form theory research of FEM in strip online rolling. In this paper, the improved rotative mid-point mensuration is presented to solve the systems of simultaneous equations obtained in FE and the study is progressed to heighten the calculating efficienc of FEM. The following are obtained:(1) The improved rotative mid-point mensuration is presented and it can provide a good value for Newton-Raphson (N-R) method. The improved rotative mid-point mensuration combining with the Newton-Raphson method designated the M-P method, which is employed to solve the nonlinear equations.(2) The idiographic computing process and procedure that the M-P method solves nonlinear equations are gived. The astringency, stability and error of the improved rotative mid-point mensuration are analyzed. The improved rotative mid-point mensuration is steady and convergent.(3) The M-P method is used to solve the equations of velocity increment in Rigid-Plastic FEM for proving its'feasibility. We use the M-P method to calculate spot data of some steelworks.(4) In this paper, it has been analyzed that the pedometer parameter influences the M-P method. The M-P method and the N-R method are compared in terms of CPU time, the number of iterations and rolling force and so on. The CPU time required for calculation of the N-R method is more than the M-P method. The computed rolling forces by the M-P method correlates better with the measured value. Numerical tests show that the M-P method is feasible and steady.