四辊轧机冷轧板带材板形问题的数值模拟

【作者】 阚志；

【导师】 陈君若；

【作者基本信息】 昆明理工大学 ， 材料加工工程， 2007， 硕士

【摘要】 板材的板形是影响板材质量和成材率的一个重要因素。它受到众多研究工作者的重视。板材的冷轧过程是一个复杂的力学过程，它是包括几何非线性、材料非线性和接触非线性的强非线性问题。板形则是研究轧制时，板材翘曲程度问题。本文叙述了与板形相关的基础知识，介绍了弹塑性有限元的理论基础，推导了大变形弹塑性有限元法的求解过程，得出了大变形弹塑性有限元的解。为本文的研究工作提供了坚实的理论基础。本文以四辊轧机为基础对软钢薄板的冷轧过程进行了有限元模拟计算。通过对实际轧制条件的系统分析，建立了有限元分析模型，其中包括：确定合理的边界条件和初始条件、选择正确的材料本构关系和屈服准则、为轧辊和轧件选择合适的单元类型、保证网格划分的合理性等。本文重点研究分析了影响板带材的板形问题的两个主要方面：辊系的弹性变形和金属的三维流动。首先应用大型有限元分析软件ABAQUS建立三维的有限元模型，应用MATLAB语言对相关公式进行编程，从而计算出轧制力的分布、估算辊间的接触区域，对辊系的弹性变形进行模拟分析，主要分析了工／支径比、支撑辊长度、轧件宽度、弯辊力、轧制力对工作辊弹性变形的影响；其次对轧制过程进行动态的模拟分析，研究了轧件宽度、压下量、弯辊力等对轧后板带材的压下量、金属的横向流动和板材内部残余应力的影响。文中还对刚性辊和弹性辊条件下的分析结果进行了对比分析，进一步验证了弹性辊分析结果的正确性。本文通过大量的有限元模拟分析得到了各因素对辊系弹性变形、板形和金属塑性流动的影响规律；对物理实验和实际生产有一定的指导作用。更多还原

【Abstract】 The profile of strip is one of important factor that affect the quality and ratio of finished product of strip. Many researchers attached importance to it. The cold rolling is the complicated process that includes geometry non-linearity, material non-linearity and contact non-linearity. The profile of strip is the problem that researches the uniformity of strip portrait.In the paper: the correlative foundation knowledge of profile is narrated, the foundation theory of elastoplasticity finite element system is introduced, the solution process of big elastoplasticity finite element method is deduced. These works provides theory foundation for the research of the paper.The four rollers rolling mill is basal model in the paper, elastoplasticity finite element method is used to simulate the cold rolling process. The fact rolling process is seriously analyzed, correct elastoplasticity finite element model is founded. It includes to make sure of the reasonable boundary and original condition, to choose correct material stress-strain relation、yield criterion and the sort of element , to ensure the rationality of mesh . Two aspects of effect factors of profile is emphatically studied in the paper: the elasticity deformation of work roll and three dimensions plastic deformation of metal .The first, the elasticity deformation of roller is simulated by using finite element analysis software. erecting finite element analysis model、applying Matlab to program to calculate the rolling power and estimating the contact area between work and back roll is included to this part; diameter ratio of work and back roll、length of back roll、width of strip、bending force of work roll and rolling force affecting the elasticity deformation of work roll is researched. The second, elastoplasticity finite element method is used to simulate the dynamic process of rolling. In this part, the sorts of effect factors of profile is analyzed in the paper; width of strip、rolling reduction ratio and bending force of work roll affecting of profile and three dimensions plastic deformation of metal is researched. Besides upwards aspects, the paper contrasted the analysis results of rigidity roller and elasticity roller to proof the analysis result of elasticity roller rolling process to be true.By the detailed analysis, the paper gained the rules that the sorts of factors affecting elasticity deformation of roller and three dimensions plastic deformation of metal. Those rules can guide physical experiments and fact manufacture. The results of the paper accelerate the application of using finite element method to resolve the problem of profile.更多还原