钢轨万能轧制过程轨头和轨底成形理论研究及数值模拟

发布时间：2018-04-10 20:15

本文选题：钢轨 + 万能轧制　；参考：《燕山大学》2015年硕士论文

【摘要】：为了满足经济快速发展的需要,我国正在快速实现铁路运输系统的高速化、重载化。钢轨作为铁路系统的基础设施,其尺寸精度、性能和强度是制约铁路运行速度的重要因素。目前钢轨万能轧制过程的研究主要集中在设备改造和工艺改进上,理论研究也主要依靠有限元软件进行数值模拟或实验来完成,这对提高钢轨性能来说进展比较缓慢。随着钢轨万能连轧技术和自动化控制技术的快速发展,建立精确的万能轧制数学模型变得越来越重要。本文以简化后钢轨三维几何模型为基础,研究了轨头和轨底宽展规律、轨头和轨底内侧变形区中性线方程及其单位压力分布规律,给出了准确的计算轨头和轨底变形区的单位压力公式,探讨了钢轨轧制过程中轨头和轨底的搓轧成形机理。首先给出钢轨简化后的三维几何模型,推导出万能轧制过程轨腰变形区、轨头及轨底变形区的面积计算公式,并且基于秒流量相等规律推导轨头内侧及轨底内侧和水平辊侧面接触区的中性线方程(三维曲线),利用MATLAB编程软件绘图分析不同压下系数组合情况下中性线位置变化。其次,将轨头和轨底变形区离散成许多微单元体,研究微单元体上的平衡条件,建立万能轧制时轨头、轨底变形区的三维近似平衡微分方程式,并得到轨头、轨底接触变形区单位压力分布公式。在此基础上利用MATLAB编程软件绘图分析不同压下系数组合情况下对单位压力的影响。最后,在DEFORM-3D有限元分析软件中,建立钢轨万能轧制的热力耦合有限元模拟计算模型,并进行有限元模拟得到钢轨万能轧制过程中的各道次的轨头和轨底内侧变形区单位压力分布图以及摩擦力分布图。通过将理论计算结果与数值模拟结果进行对比可知:理论公式计算结果与钢轨万能轧制模拟结果比较接近,可以应用于钢轨实际生产中计算轨头和轨底变形区单位压力。通过对轨头和轨底变形区摩擦力分析,探讨了轨头和轨底搓轧成形过程。
[Abstract]:In order to meet the needs of rapid economic development, our country is rapidly realizing the high-speed and overloading of railway transportation system.As the infrastructure of railway system, rail size accuracy, performance and strength are important factors that restrict the speed of railway operation.At present, the research of rail universal rolling process is mainly focused on the improvement of equipment and technology, and the theoretical research is mainly completed by the numerical simulation or experiment of finite element software, which is slow to improve the rail performance.With the rapid development of universal continuous rolling technology and automatic control technology, it is more and more important to establish accurate universal rolling mathematical model.Based on the simplified 3D geometric model of rail, this paper studies the law of rail head and rail bottom width, the neutral line equation of rail head and rail bottom inner deformation zone and the distribution law of unit pressure.The formula of unit pressure for calculating the deformation zone of rail head and rail bottom is given, and the forming mechanism of rail head and rail bottom during rail rolling is discussed.Firstly, the simplified 3D geometric model of rail is given, and the calculation formulas of rail waist deformation zone, rail head and rail bottom deformation area are derived.Based on the law of equal flow rate per second, the neutral line equation of the inner side of the guide rail head, the inner side of the rail bottom and the lateral contact area of the horizontal roll is derived (3D curve), and the change of the neutral line position under the different pressure coefficient combination is analyzed by using MATLAB programming software.Secondly, the deformation zone of rail head and rail bottom is discretized into a lot of micro element bodies. The equilibrium conditions on the micro element body are studied, and the three dimensional approximate equilibrium differential equation of rail head and rail bottom deformation zone during universal rolling is established, and the rail head is obtained.The formula of unit pressure distribution in contact deformation zone of rail bottom.On this basis, MATLAB programming software is used to plot and analyze the influence on unit pressure under the condition of different pressure-drop coefficient combination.Finally, in the DEFORM-3D finite element analysis software, the thermal coupling finite element simulation model of universal rail rolling is established.The unit pressure distribution diagram and friction force distribution diagram of rail head and inner deformation zone of rail bottom are obtained by finite element simulation during universal rail rolling.By comparing the theoretical calculation results with the numerical simulation results, it can be seen that the theoretical formula results are close to the results of rail universal rolling simulation, and can be used to calculate the unit pressure of rail head and rail bottom deformation zone in the actual production of rail.Based on the friction analysis of rail head and rail bottom deformation zone, the forming process of rail head and rail bottom is discussed.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG335.43

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