Application Of Modified Gradient And Newton Method In Flat Rolling

In the strip rolling process, Finite element method (FEM) is an efficacious computational algorithm. Heightening the calculating efficiency in the precondition of ensuring calculating precision has been the key issue in solving problems of on-line application. In recent years, many numerical methods have been used in rigid plastic FEM and improved the speed of calculation, making the research of on-line application some progress. In order to heighten the calculating efficiency of FEM further, this paper presents an algorithm that can speed up the solving speed of FEM and discusses the on-line application initially. The main contents are as follows:(1) Modified gradient and Newton method (for short MGN method) is presented. Modified gradient method decline most quickly, in the beginning, each of iteration can make the function decline significantly. Therefore, modified gradient method can find a good initial value for Newton method quickly. Modified gradient and Newton method a good combination of two methods, has global convergence.(2) Modified gradient and Newton method's probability is tested. We select many groups of steel rolling data and use N-R method, MFC method and MGN method to calculate them respectively. Then CPU time, rolling force and power function minimum are compared and analyzed.(3) N-R method and MGN method's calculating results are compared in different element dividing. The paper analyzes the number of iterations, CPU time and rolling force how to change with the element numbers increasing. In different element dividing, MGN method calculates faster always than N-R method and the calculation with rolling force is in good agreement with the measured. Data experimental certificates the MGN method to be efficient and steady in the sheet metal rolling.