A main feature of special shape strips is the local residual deformation on a normal flat. This paper considers a numerical simulation of the rolling of strips with longitudinal ribs as an example, to analyse the influence of friction variation on the convergence and results of simulation such as rolling force, rib height and forward slip by a 3-D rigid visco-plastic Finite Element Method (FEM). The effects of mesh division and the number of elements on the precision, stability and convergence of simulation are also discussed. This investigation shows that a frictional stress model with a variation in the deformation zone can provide satisfactory results. Suitable mesh division can improve the precision and convergence of simulation. The simulation coupled with temperature field is also discussed, and the results are in good agreement with experimental values.