基于流面条元法的四辊热带钢连轧机整机仿真

用流面条元法分析带材的三维塑性变形，用影响系数法分析辊系的弹性变形，将二者联立，组成板形和板凸度的分析和计算模型，对1450mm四辊热带钢连轧机的轧制过程进行了仿真，仿真结果与实测结果吻合良好，为四辊热带钢连轧机板形分析与控制的仿真提供了模型和方法。     

四立柱分体式20辊轧机辊系的刚度特性分析

20辊轧机的横向刚度、纵向刚度对板形、板厚的控制非常重要,研究不同状态下轧机的刚度变化规律对板形、板厚综合控制的精度具有十分重要的意义。在三维弹性有限元模型的基础上,建立了四立柱分体式20辊轧机辊系的有限元模型。利用该模型研究板宽、中间辊窜辊量变化对轧机辊系横向刚度和纵向刚度的影响,为轧机板形、板厚控制量的调整提供了参考依据,也为板带轧制过程中板型、板厚在线设定,以及控制模型的研究和优化,提供了理论基础。     

板形自动控制在热连轧中的应用

莱钢1500热连轧生产线的板形自动控制系统是国内自主研发的板形控制系统,它包括板预设定形、板形的PID调节、弯辊力的前馈控制、凸度仪的反馈控制、窜辊的闭环调节、平坦度的反馈控制、板形与板厚的解耦控制等多种控制于一体。主要介绍弯辊力前馈、凸度反馈和平坦度反馈3个模型在实际轧钢过程中的应用。     

基于辊缝动力学的板带轧机垂直振动的研究

板形与板厚是衡量板带轧制成品几何精度的两大指标。而与这些指标直接相关的是轧机机座垂直方向的振动。本文将机座与轧件作为一个系统来研究 ,建立了基于辊缝动力学的 ,以分析板带轧机机座垂直振动对板形及板厚影响为目的辊缝动力学模型 ,提出了振动模态对板形及板厚影响的指标。得出的结论是 :板形与板厚控制的实质是辊缝的控制 ,在轧制状态下辊缝不仅与静力学因素有关 ,而且在很大程度上取决于辊缝动力学因素。本文所建立的模型考虑了阻尼因素及由辊缝动力学模型确定的非线性轧制力 P,使模型能更真实的模拟现场实际情况     

四辊CVC热带钢轧机板形控制特性的仿真

用流面条元法分析带材的三维塑性变形．用影响系数法分析辊系的弹性变形，将两者耦合，建立了四辊轧机板形和板凸度的分析计算模型。对四辊CVC热带钢轧机板形控制特性的仿真表明，随着CVC工作辊横移距离的增加，前张应力沿横向的差距增大；随着工作辊弯辊力的增加，前张应力沿横向的差距增大，且变化主要集中在板宽的边部；随着板宽的增加，前张应力沿横向的差距先减小后增大。     

板带轧机板形控制倾辊弯辊神经模糊PID模型

板形是板带轧制的重要质量指标,倾辊和弯辊是板形控制的重要手段.目前常规的PID控制算法被广泛应用到板带轧机倾辊和弯辊板形控制系统中,但由于实际系统随机干扰严重,具有多变量、非线性、强耦合的特征,难以建立较为准确的数学模型,常规的PID控制算法很难满足板形高精度控制的要求.为能提高倾辊和弯辊板形控制系统的性能,在常规PID控制算法的基础上,建立基于神经网络的模糊PID倾辊弯辊板形控制模型,通过神经网络的自学习能力和模糊控制的"概念"抽象能力的有机结合寻找一个最佳的P、I、D非线性组合控制律,增强对控制环境变化的适应能力和自学习能力.仿真试验结果表明,该模型能很好地跟踪板形的目标设定值,响应快,超调小,鲁棒性强,可提高倾辊和弯辊对板形的控制精度,为板形高精度控制提供了一种新方法.     

HC轧机板形板凸度控制特性的计算机模拟

用三次样条流线条元法分析带材的三维塑性变形，用影响系数法分析辊系的弹性变形用，BP神经网络方法对轧后带材板形进行模式识别，将三者联立，对900mmHC轧机板形板凸度控制特性进行了计算机模拟。结果表明：HC轧机控制二次板形能力很强，对四次及更高次板形控制能力较弱；中间辊横移和工作辊弯辊对板形板凸度的控制需要相互配合。对板凸度的控制应着重在开始道次进行。     

万能凸度轧机非对称板形调控特性与广义整体板形控制策略研究

随着板形质量精度要求的不断提高以及板形控制技术的显著进步,非对称板形缺陷逐渐凸显为带钢轧制质量控制的重要技术难点。根据目前新建万能凸度轧机(Universal crown mill,UCM)逐渐具备新型非对称板形控制手段——反对称弯辊的有利条件,通过ANSYS有限元仿真计算软件,建立高精度辊系—轧件一体化耦合模型,分析UCM各对称与非对称板形控制手段沿带钢全宽调控特性的差别,并以板形调控功效矢量的形式进行定量表示。在仿真基础上,提出基于板形调控功效矢量的广义整体板形控制策略,并设计完整的板形设定计算模型与闭环控制模型。通过仿真试验表明,该控制策略能够很好地通过各对称与非对称板形控制手段的有效配合实现对复杂模态板形的有效控制,具有广阔的研究与应用前景。     

动态板形辊平整机板形控制机理模型研究

建立了动态板形辊（DSR）平整机板形控制特性分析的理论模型。综合考虑了DSR技术独特的板形控制机理,以及其空心辊套和分段压块的特殊结构,基于分割模型的影响函数法,建立了DSR平整机辊系变形的理论模型;在此基础上,考虑平整轧制的特殊要求,将针对平整过程的金属模型和辊系模型进行耦合计算,建立了板形控制分析的整体模型,并编写了模型的计算流程和程序,以此对DSR平整机的板形控制能力进行研究。     

四辊轧机有载辊缝解析模型研究

针对轧制过程中轧辊的弹性变形和轧辊与轧件间的相互作用，通过对四辊轧机辊系变形和受力状况的分析，从理论上详细推导了直观的有载辊缝形状函数，明确了有载辊缝形状函数与相关因素的对应关系。同时，为了验证辊缝解析模型的准确性，采用该模型对某铝热连轧机的精轧末机架的出口板凸度进行了理论计算，并与在线测得数据进行比较，结果表明：该模型计算精度高，相对误差较小(低于15％)。该模型不但为板形的控制以及轧制板凸度的建模提供了理论基础，还为预报板形、研究板带截面上任一点的板凸度提供了方便。     

带材轧制过程应力及变形的计算机仿真

用三次样条流线条元法分析带材的三维塑性变形,用分割模型影响系数法分析辊系的弹性变形,用BP神经网络方法对轧后带材板形进行模式识别,将三者联立,对900 mm HC轧机冷轧带材轧制过程进行了计算机仿真,得到了较为详细的应力及变形的仿真结果。仿真实例表明,提出的方法和模型符合实际,对三维轧制理论、板形理论及控制技术的发展有重要意义。     

Coupled dynamic modeling of rolls model and metal model for four high mill based on strip crown control

The crown is a key quality index of strip and plate,the rolling mill system is a complex nonlinear system,the strip qualities are directly affected by the dynamic characteristics of the rolling mil.At present,the studies about the dynamic modeling of the rolling mill system mainly focus on the dynamic simulation for the strip thickness control system,the dynamic characteristics of the strip along the width direction and that of the rolls along axial direction are not considered.In order to study the dynamic changes of strip crown in the rolling process,the dynamic simulation model based on strip crown control is established.The work roll and backup roll are considered as elastic continuous bodies and the work roll and backup roll are joined by a Winkler elastic layer.The rolls are considered as double freely supported beams.The change rate of roll gap is taken into consideration in the metal deformation,based on the principle of dynamic conservation of material flow,the two dimensional dynamic model of metal is established.The model of metal deformation provides exciting force for the rolls dynamic model,and the rolls dynamic model and metal deformation model couple together.Then,based on the two models,the dynamic model of rolling mill system based on strip crown control is established.The Newmark-β method is used to solve the problem,and the dynamic changes of these parameters are obtained as follows:(1) The bending of work roll and backup roll changes with time;(2) The strip crown changes with time;(3) The distribution of rolling force changes with time.Take some cold tandem rolling mill as subject investigated,simulation results and the comparisons with experimental results show that the dynamic model built is rational and correct.The proposed research provides effective theory for optimization of device and technological parameters and development of new technology,plays an important role to improve the strip control precision and strip shape quality.     

板带热轧三维有限元热力耦合仿真分析

采用更新的Langrange方法及大变形热力耦合有限元法对热轧过程进行了热力耦合仿真分析,经过多道次轧制仿真后,得出了轧件的温度场和轧制力分布以及每道次轧件入口与出口温度大小及轧制力的大小,并进行了现场工业实验对仿真结果进行了验证,计算结果表明,仿真所得结果与实测结果误差很小,均在5%之内,从而证明模型是正确的,能够很好的运用于热轧过程的参数计算和研究,并对以后热轧工艺参数匹配规律研究以及板形控制研究提供重要的分析平台和起到重要的指导作用.     

STUDY ON STRIP AND ROLL DEFORMATION COUPLING OF COLD STRIP ROLLING ON 4-H MILL

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板材调宽轧制头部形状控制有限元分析

利用数值仿真技术建立立轧／平轧三维热应力耦合有限元模型，对宝钢2050粗轧区实际工况进行仿真计算。计算所得的带钢头部形状与实测结果吻合很好，说明所建模型合理且有效。针对宝钢2050现场轧制实际问题，研究了立轧／平轧过程带钢头部的非稳态变形规律，给出了立轧头部等效应力、等效应变及厚向位移分布规律。根据模拟计算数据建立控制带钢头部形状的短行程控制模型。通过对比分析可知，所得新模型比原模型能更好地改善头部形状及减少切损量。     

An investigation of contact problem between strip and work roll with a smooth straight surface during cold rolling

Under the assumption of elastic roller, and the neglect of heat transfer problem, this paper explores the distribution of elastic deformation of the work roll with initially smooth straight surface in the rolling area during the rolling process, and analyzes the effect of this deformation distribution on the strip shape after rolling.

Based on the large deformation—large strain theory, the update Lagrangian formulation (ULF) and the incremental principle were used to develop 3D elastic-plastic analytical model of aluminum strip rolling. The flow stress was considered the function of strain and strain rate to infer the governing equation containing the effect of strain rate.

Besides, in this article, we propose an iteration procedure to calculate the contact force between strip and work roll, and the contact deformation of the work roll. In the treatment of the contact problem, the work roll was regarded as a rigid body at the beginning of each step. The incremental displacement and contact force of strip nodes were first calculated, and then entered into the first iteration loop. The contact forces of strip nodes were allocated to the work roll to calculate work-roll elastic deformation. The elastic deformation of work-roll nodes would be compensated to the incremental displacement of the strip nodes (the work-roll deformation increment was added on the incremental displacement of strip node). Then the new contact nodal forces were derived from the finite element program of strip. The above procedures were repeated to incorporate the new contact nodal forces into the first iteration loop to obtain the new strip node incremental displacement. An error range was also designated as the comparison standard to compare the displacement increments of the strip from two iterations to determine whether the iteration was completed.

This paper considers the initial shape of work roll is straight and smooth. The elastic deformation distribution on the work roll surface in the rolling area is analyzed to serve as the basis for work-roll radius compensation. Finally, deformation of strip shape is also discussed.     

Control Scheme Using Forward Slip for a Multi-stand Hot Strip Rolling Mill

Forward slip is an important parameter often used in rolling-speed control models for tandem hot strip rolling mills. In a hot strip mill, on-line measurement of strip speed is inherently very difficult. Therefore, for the set-up of the finishing mill, a forward slip model is used to calculate the strip speed from roll circumferential velocity at each mill stand. Due to its complexity, most previous researches have used semi-empirical methods in determining values for the forward slip. Although these investigations may be useful in process design and control, they do not have a theoretical basis. In the present study, a better forward slip model has been developed, which provides for a better set-up and more precise control of the mill. Factors such as neutral point, friction coefficient, width spread, shape of deformation zone in the roll bite are incorporated into the model. Implementation of the new forward slip model for the control of a 7-stand hot strip tandem rolling mill shows significant improvement in roll speed set-up accuracy.