WANG Tao
,
XIAO Hong
,
ZHAO Tie-yong
,
QI Xiang-dong
钢铁研究学报(英文版)
In order to simulate and analyze hot strip crown and flatness accurately and efficiently, the 3-D (three-dimensional) coupled model involved in RPFEM (rigid-plastic finite element method) is improved based on the analytical model of forecasting rolling force distribution. In the analytical model, variational method is employed to solve the lateral flow of metal and influential function method is employed to calculate roll deflection, the lateral distribution of rolling force can be obtained rapidly by iterative strategy. Then the 3-D coupled model uses the result as initial distribution of rolling force to calculate roll deflection and makes the initial on-load roll gap profile close to the final value, so as to reduce iterations and increase efficiency. Compared with previous algorithms, the improved model can reduce the iterations by about 50% and shorten the computing time by about 60% on the basis of the calculation accuracy.
关键词:
rolling force
,
analytical model
,
RPFEM
,
coupled model
,
efficiency
LI Yugui
,
HUANG Qingxue
,
SHEN Guangxian
,
XIAO Hong
,
PANG Siqin
,
WANG Jianmei
钢铁研究学报(英文版)
With rollers as elastic bodies and workpieces as elastoplastic bodies, the rolling problem can be viewed as a friction elasticplastic contact problem. With fewer assumptions in the simulation of striprolling process, a boundary element method (BEM) for twodimensional elastoplastic finite strain and finite deformation analysis of contact problems with friction was presented. All the equations for contact problems, which include multinonlinearities, were obtained. Incremental and iterative procedures were used to find contact pressure and friction stress. Moreover, initial strain rate algorithm and workhardening material behavior can be assumed in the plastic analysis. Several examples were presented, and the results of contact pressure and friction stress were in excellent agreement with those of analysis.
关键词:
boundary element method;contact problem;elastoplastic finite deformation;rolling
QI Xiang-dong
,
WANG Tao
,
XIAO Hong
钢铁研究学报(英文版)
Rolling schedule not only determines the rolling process to be going smoothly, but also affects the shape accuracy and structure properties of finished strip. In order to gain good strip crown and flatness, the calculation formulas of the most suitable rolling force and bending force are deduced. By taking relatively equal load of rolling power and good shape as objective functions, the optimization mathematical models of finish rolling schedule are established. By contrast, the rolling schedules after optimization can improve the rolling mill working status and ensure the strip crown and flatness to be good. At the same time, the setting value of bending force is improved and this leaves more space for on-line shape control.
关键词:
optimization
,
rolling schedule
,
rolling force
,
bending force
,
shape
