挤压筒颤振辅助双杯挤压成形过程有限元分析

Finite Element Analysis of Double Cup Extrusion Process with Fluttering Container

阐述挤压筒颤振辅助双杯挤压成形机理,运用Deform-3D有限元分析软件进行数值模拟仿真,分析比较不同施振参数下的行程载荷、材料流动速度、杯高比及等效应力分布。仿真结果表明挤压筒颤振可降低平均行程载荷,其平均行程载荷的最大下降值随颤振速度的提高而增加,但对实际挤压力影响不明显;上杯材料流动速度随颤振速度的提高而减小,下杯材料则相反;当颤振速度小于下杯材料流动速度时,杯高比大于无颤振时的值,且随颤振速度的提高而增加,而当颤振速度大于下杯材料流动速度时,上杯材料流动速度方向会出现反向,杯高比小于无颤振时的值,并随颤振速度的提高而减小;邻近挤压筒侧的塑性变形区随颤振周期性上下运动,但并不改变最大等效应力。

The deformation mechanisms of double cup extrusion processes with fluttering container were carried out.Deform-3D was employed to simulate the present processes. The influences of the flutter on the mean extrusion load,flow velocity,cup height ratio and stress distribution were analyzed. The simulation results showed that the mean extrusion load under fluttering container decreased and the maximum reduction of load increased with the increasing of fluttering velocity. However,the effect of the fluttering on the load reduction was not significant. The flow velocity of the upper cup wall decreased with the increasing of flutter velocity,that of lower cup wall was opposite in the extrusion process of double cup with fluttering container. On the fluttering velocity below the flow velocity of lower cup wall,the value of cup height ratio was greater than that without fluttering container and increased with the increasing of fluttering velocity. On the fluttering velocity above the flow velocity of the lower cup wall,the direction of the flow velocity of upper cup wall is reversed. Moreover,the less magnitude of cup height ratio was attained and sharply decreased with the increasing of fluttering velocity. The cyclical shift of deformation zone adjacent to container and the almost constant of the maximum stress in the extrusion process with fluttering container were observed.