三辊行星轧机轧制过程力分析

【作者】 黄勇；

【导师】 张海兵；

【作者基本信息】 昆明理工大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 目前,国内外金属轧制生产技术的发展趋势是：大规模生产的高效化、短流程工艺、生产线连续作业、环境污染和能耗小。三辊行星轧机是最具代表性的短流程关键设备,其优点是单道次变形量大和良好的无扭连轧特性,可用于轧制钢、有色金属和一些难变形的合金材料,在棒材、线材和管材成型中获得日益广泛的应用。就国内外三辊行星轧机的理论研究而言,虽然取得了一定的研究成果,但仍有许多问题尚待研究。本文分别用传统的理论方法和有限元仿真的方法,对轧件的变形过程和轧制力能参数进行研究。论文简要叙述了三辊行星轧机的产生与发展、传动原理及其优点与不足。在总结前人研究设计轧机成果基础上,借助于已建立的轧件变形区微分几何模型和对轧辊与轧件几何关系的研究,详细分析了轧辊与轧件的接触面。根据卡尔曼单位压力微分求解原理,得到轧件变形区的单位压力表达式,进而推导出计算轧制力和轧制力矩的积分式,并采用数值分析的方法对其进行精确计算。根据实际轧制条件,选取适当的轧制参数,应用Visual Basic语言编程计算,获取轧制力、轧制力矩和电动机的功率。论文根据有限元法的基础理论,推导了大变形弹塑性有限元法和显式动力学有限元法的求解过程,成功利用有限元分析软件ANSYS/LS-DYNA对三辊行星轧机轧制的弹塑性大变形过程进行有限元仿真计算。在对轧机各主要部件进行合理简化的基础上,采用坐标变换的方法,将轧辊的轴线和轧件的中心线准确地在ANSYS/LS-DYNA软件中定位,建立起轧辊与轧件的三维实体有限元模型。根据仿真数据,对轧件的形状、等效应力和应变分布、轧制负荷以及轧件速度进行分析,讨论了转化轮系传动比和螺旋运动参数,确定了轧件中性面位置。论文采用传统的理论和编程计算轧制力能参数的方法,提高了计算效率,便于工程上的应用。基于ANSYS/LS-DYNA软件进行的有限元仿真分析,为进一步认识轧制过程中轧件的成形规律打下了基础,也为轧机设计提供了依据。更多还原

【Abstract】 At present, the domestic and foreign metal rolling technology trend of development is:the large scale production by highly efficiency, the craft of short flow, the production line continued operation, the small environmental pollution and the low energy consumption. Three-roll planetary mill (PSW) is the most representative short flow essential equipment. The large deformation in a single pass and good capability of no-torsion continuous rolling are its merits. PSW can be used to roll steel, non-ferrous metals and hard deforming alloy material. In the formation of rod, wire-rod and tubing, it is used widely day by day. Speaking of the domestic and foreign theoretics study on PSW, although it has acquired certain research results, it still need to be studied in many respects. This paper separately uses traditional theory method and finite element method to research workpiece’s deformation process and rolling force.The paper briefly narrates emergence, development, transmission principle, merits and faults of PSW. On the basis of summarizing predecessors’research results of designing PSW, contact area has analyzed in detail with the differential geometry model and geometrical relationship research between roller and workpiece. According to the differential principle which Kalman solves unit pressure, unit pressure of the deformed area is obtained. And then the integral equation of rolling force is gotten. Finally the rolling force and rolling torque are obtained by means of numerical analysis method. On the basis of the actual rolling condition, the paper selects suitable rolling parameters and uses the software of Visual Basic to program. We can get the rolling force, the rolling torque and the power of motor.According to the basic theory of finite element method, the solution process of big elastoplastic finite element method and explicit dynamics finite element method are deduced. The author uses triumphantly finite element analysis software ANSYS/LS-DYNA to do the elastic-plasticity large deformation process’emulational calculation of rolling process. Each major component of PSW is used to predigest the rational model for the tridimensional entity finite element model. It uses the transformation of coordinates together with the accurate position of roller axes and workpiece center line. According to the simulation data, we can analyze workpiece shape, distribution of the equivalent stress and strain, rolling force, workpiece velocity, transmission ratio of wheel train, spiral movement parameter and position of the neutral plane.The paper uses the traditional theory and programming to calculate rolling force. This method has the merit of high computing efficiency. It is easier to be used in the engineering application. The finite element simulation analysis is based on the software of ANSYS/LS-DYNA. It can establish the foundation for the advanced realization of workpiece forming law, and offer reference to design the PSW.更多还原