Force Analyze And Calculate Of Dragon Rolling Mill And Bending Analyze And Control Of Rolling Plate

Abstract:With the development of a new generation of aircraft, aircraft structures present a trend of large-scale and integration, putting forward the urgent demand to big thickness aviation aluminum alloy pre-stretching plate. While in the hot rolling process to manufacture thick aluminum alloy, traditional symmetrical rolling is difficult to make the deformation into the core of plate, cause the problem of non-uniform of organization and performance between the surface and core, high residual stress. Dragon rolling can make the deformation into the core of thick plate, increase the shear deformation of thick plate core, thus enhance the homogeneity of organization and performance of plate. Therefore, this paper researched on the force of dragon rolling mill and the bending law of plate, has a important significance to design and manufacture of dragon rolling mill and lay down process rules of dragon rolling.Firstly, the implementation forms of dragon rolling was researched, according to the force characteristic of dragon rolling deformation zone, the expression for calculating rolling force in dragon rolling was worked out. Then, the forces of rolls and roll stand in dragon rolling mill were analyzed. The rolling stand in dragon mill must bear greater horizontal force than in conventional mill.Secondly, based on the force analysis result of rolling stand, the strength and stiffness of rolling stands of conventional mill and dragon mill with different offset forms were analyzed and compared by MSC.Marc software. The influences of speed ratio, offset distance on the rolling force and stress of mill stand in dragon rolling were studied.Thirdly, the thermal-mechanical coupled model of dragon rolling was established based on MSC.Marc software. And the influence of dragon rolling process parameters such as plate entrance thickness, reduction, speed ratio and offset distance on plate bending was researched. The plate bending can be controlled by adjusting offset distance. The best offset distance in different process conditions were obtained, a mathematic model of best offset distance for controlling the plate bending was constructed. Finally, by the dragon rolling experiment of aluminum alloy thin plate, the bending values of different plate entrance thickness, reduction, speed ratio and offset distance were measured; the stresses of mill stand in dragon rolling and symmetrical rolling were also measured. Experimental results and simulation results were consistent; the accuracy of finite element model was verified.