扁挤压筒内铝型材挤压的上限研究

Upper bound analysis for extrusion of aluminum shape in flat container

应用上限法建立了扁挤压筒内铝型材挤压的等挤压比流动模型 ,得到了 3次多项式表示的流线方程 ,给出了变形区的动可容速度场、应变速率场及上限功率的表达式 ,获得了最优上限挤压应力的数值解 ;分析了挤压比、挤压筒截面及型材截面形状等参数对挤压力的影响 ,得到不同长宽比A/B的扁挤压筒内挤压应力的计算线图 ,具有实用价值。理论计算与实验结果吻合很好 。

In this paper, the upper bound method is used to build the extrusion flow model of Aluminum Shape in Flat Container ,i.e. the model of indentical extrusion ratio.The flow equation is established with 3rd order polynome. The kinematically admissible velocity field , the strain rate field and the deformation power are formulated. The optimum numerical solution of the relative stress is obtained. The effects of extrusion ratio , the section of container and the product on the extrusion force are analyzed. The calculated curves of the relative stress for various A/B ratio of the container are obtained. They are useful.The theoretical results are compared with known experimental data and are found to be in good agreement.