【作者】 赵颖；

【导师】 宋宝韫；

【作者基本信息】 大连交通大学 ， 材料加工工程， 2006， 硕士

【摘要】 用有限元法模拟金属塑性成形过程已成为塑性成形研究的中心问题。由于各种塑性成形模拟软件发展水平的限制，还不能完全利用模拟软件来对铝管连续挤压这样复杂的成形过程进行分析研究。为了解决这个矛盾，我们将实际中复杂的塑性成形过程进行简化，再利用有限元模拟软件进行模拟，来获取所需要的主要信息，为实际生产服务。 本文采用DEFORM有限元数值模拟软件，对铝管连续挤压变形过程以及模腔内金属流动的均匀性等问题进行了研究。研究内容主要分两部分进行。 第一部分分析铝多孔扁管的连续挤压过程。通过对几何模型、变形过程采取适当的简化，以及增加一个假想“对称面”解决从分流孔流出的金属在对称面上无约束的问题，成功地实现了数值模拟研究。通过分析模拟结果，可以直观地了解金属在平面分流组合模通道中的流动特点，并掌握多孔管挤压模具所需重点解决的问题：在保证模具强度的同时，使金属流动均匀。得出的金属温度分布曲线与实测温度基本吻合。这些模拟结果对连续挤压铝多孔扁管的生产工艺设计及分流组合模的设计等都有重要的指导作用。 第二部分针对连续挤压生产本身金属流动不均匀是否导致挤压铝圆管时出现竹节纹缺陷这一问题，进行了数值模拟分析；并对几种均衡金属流速的方案进行了对比研究。通过去掉凹模以解决模拟过程中网格自接触的问题，使模拟过程得以实现。并设计分析方法，通过比较金属在各分流孔之间流动的均匀性判定参数δ，得出结论：连续挤压本身结构的特点所造成的变形金属流动至腔体进料口处时所产生的速度差异，不会导致竹节纹缺陷出现；采用通用的铝材连续挤压腔体，使用具有3个分流孔的分流组合模时，将凸模的一个分流桥放置在堵头侧对称面上，是均衡金属流速的最佳生产方案。 本研究将有限元模拟技术与铝管连续挤压的生产实际紧密结合，体现了科技为生产服务的宗旨，有广阔的应用前景。更多还原

【Abstract】 Simulating the metal plastic forming process by finite element method has become a crucial question in the plastic forming study. Limited by the development level of each plastic forming simulation software, the complex forming process of continuous extrusion for aluminum tubes can not be completely analysed using simulation software. In order to resolve this contradiction, we carry on the simulation study by simplifying the intricate plastic forming process and then simulate the process using the finite element simulation software to obtain the main information. The results of the simulation can serve for practice.This paper analyses the deformation process of continuous extrusion for aluminum tubes and the uniformity of the metal flow in the mould cavity using the FEM simulation software DEFORM. This article is mainly made of two parts:The first part is analysing the forming process of the continuous extrusion for the aluminum multi-hole flat tubes. By simplifying the geometry model and the deformation process, as well as adding an "imaginary symmetrical plane" in order to solve the non-restriction problem in symmetrical plane after the metal flowing from the porthole, we implement the numerical simulation study successfully. By analysing the simulation results, we can understand the metal flow characteristics in the porthole die, at the same time master the key problem of the die: make the metal flow uniformity at the same time keep the die’s strength. Obtain the metal temperature distribution curve which is in agreement with the actual measurement temperature. Furthermore designing the production technology and the die of the continuous extrusion for aluminum multi-hole flat tubes can be guided through these results.The second part is the simulation study on the question of whether the nonuniformity of metal flow produced by continuous extrusion process itself can result in bamboo-shaped defect, and defferent plans of equilibrating the metal更多还原