应用UBET优化开式模锻中连皮厚度参数

连皮厚度是开式模锻工艺参数中的一个重要参量，它对模锻变形力和材料的消耗有很大的影响。本文应用上限单元法（ＵＢＥＴ）对连皮厚度进行了优化设计。基于连皮厚度和飞边高度间的相对大小关系，建立了三种不同的变形流动模式和动可容速度场，根据上限原理和黄金分割法，利用ＴｕｒｂｏＣ语言编程求解，获得了最大锻造力的最佳上限解，并和实验相比较，两者吻合得较好，表明建立的动可容速度场是合理可行的。以最大锻造力和连皮体积的乘积作为优化准则，更好地得到了最佳连皮厚度值。

Applying UBET to Optimize the Web Thickness in Closed Die Forging

Web thickness is one of the important parameters in Closed-die forging process,which has an effect on forming force of die forging and material consumption.In this paper,the optimum design of web thickness is done by Upper Bound Element Technique(UBET),Based on the relation of the web thickness and the flash height,three kinds of deformation flow models and kinematically admissible velocity fields are established,and the optimum upper-bound solution of maximum forging force identical with the experimental result is obtained by Upper Bound Theory,Golden section method and programme compiled using Turbo C language.It is shown that the kinematically admissible velocity field designed is reasonable.Taken the product of maximum forging force and web volume as an optimigation rule,the optimum web thickness can be obtained.