【作者】 刘伟；

【导师】 高锦张；

【作者基本信息】 东南大学 ， 材料加工工程， 2006， 硕士

【摘要】 目前,铝合金型材在日常生活及生产领域应用越来越广泛,用挤压的方法生产铝型材,既节约金属又具有很高的生产效率,因此该方法在生产和研究领域都日益受到重视。在铝型材挤压工艺生产中,经常凭借经验和反复试模修模来进行模具设计,不可避免的造成人力与物力的耗费。随着CAD/CAE技术在实际生产中的广泛应用,本文以平面分流组合模挤压Al6063多腔壁板型材为研究对象,通过三维造型软件Pro/Engineer创建了多腔壁板铝型材平面分流组合模型,利用刚塑性模拟软件Deform-3D对型材挤压过程进行了模拟,从而实现了对模具参数的优化。本文首先论述了平面分流组合模具的设计原则,简单介绍了刚塑性有限元理论和金属流速的判据公式,从工艺因素和几何因素方面系统介绍了影响挤压金属流动的因素。为了定量的反映几何因素在型材挤压时对金属流速的影响,利用数值模拟的方法得出了工作带长度与金属流速的关系以及局部挤压比、模孔位置、模孔的挤压工作带面积和工作带长度之间的关系。最后通过对图形文件的输入、网格细分技术,步长增量的选取以及自接触等模拟关键问题的探讨,成功地对多腔壁板铝型材挤压过程进行了模拟,得到了一组比较理想的模具参数。本文创新性地对平面分流组合模的结构进行了一些改进,提出了分流宽展模结构和流线模结构的设计思想,为壁板类铝型材挤压模具优化设计提供了全新的思路。通过模拟分析的结果可以看到,在分流孔中进行宽展不仅降低了因为单独使用宽展模具而增加的挤压力,而且可以挤压比圆挤压筒直径更宽的壁板型材。而把流线模型应用在分流模具上可以有效的降低型材挤压时的挤压力,为一些由于挤压力过高而难以挤压成形的型材提供了一种模具设计的方案。从模拟结果中可以清楚地获得挤压过程的载荷形成曲线、应力应变分布以及模具出口处的金属流速情况,便于掌握金属的流动规律,从而提高模具设计质量和效率,实现模具开发的高质量、低成本、短周期。更多还原

【Abstract】 For the present, the use of aluminum alloy profile becomes more and more popular. Extruding method is commonly used in the production, because it can not only economize raw material, but also has high productivity. So it is taken into account increasingly. However, die design often depends on the experience and trial-and-error over and over in production. With the development of CAD/CAE in production, AL6063 alloy Lacunaris panel profile is analyzed. The porthole die are designed by using CAD software Pro/Engineer and the process of extrusion are simulated by Rigid-Plastic FEM software Deform-3D.Firstly, design principle of the porthole die is produced, it introduces the theory of rigid-plastic FEM simply and the material flow velocity criterion. From technology and geometry aspect, the influence factor of material flow is introduced. Secondly, utilizing the method of numerical simulation to get the concrete influence of geometry factor in profile extrusion, it obtains the relationship between the bearing length and exit velocity, also it obtains the relationship between the bearing length and local extrusion ratio, the effect of major parameters of die structure on material flow velocity has been integrated and the general formula of bearing length design and calculation of Al profile extrusion have been derived. The correct controlling data are insta11ed and the simu1ation strategy are applied,for instance,to select the rational time-step,mesh fine,adjust the aberrance element,set right boundary conditions and so on,so the simulation process is carried out successfully.It gives some innovation of the porthole die structure creatively, and put forward the idea of the porthole-expanding die and the streamline die. By analyzing the simulation results, the porthole-expanding die not only reduce the load of extrusion but also produce the alloy profile more wider than round extrusion chamber, and the streamline die can reduce the load of extrusion effectively. The data are obtained from the Post-Processor of DEFORM-3D as the graph of Load-Stroke,the effective strain and stress distribution of the work piece and the exit velocity of material flow. It must be improve the quality and efficiency of mold design and carry out the high quality, low cost and short period of mold development.更多还原