建模与优化为20 - H的冷连轧课程毕业设计外文文献翻译@中英文翻译@外文翻译

附录 -外文翻译 Modeling and optimization for a 20-h cold rolling mill QUALITY and its reproducibility are dominant criteria for cold rolled products.In particular,high strip surface quality can be achieved with special mill arrangements such as the 20-h mill.This type of mill uses small work rolls in contact with the strip,that are kept in place with a variety of intermediate and backup rolls.The use of different actuators which,in part,only act indirectly to affect the roll bite geometry,makes the presetting of the mill with regard to strip thickness and flatness a complex task. This article describes a model the objective of which is optimizing the entire rolling process in a 20-h mill.Results obtained from several on-line applications are discussed. A closed sendzimirmill arrangement,shown in Fig.1,illustrates the main actuators that affect roll bite geometry with regard to strip thickness and glatness.Side eccentrics located at the backup rolls are used to adjust the overall position of the corresponding roll axis over a wide range which,indirectly,adjusts the roll gap geometry with regard to the millpassline and strip thickness.Side eccentrics may be mechanically or electrically coupled.Crown eccentrics are available at several locations over the barrel length.Those,typically on upper backup rolls,are capable of providing special roll gap contours.They match the gap to the profile of the strip entering the mill.Crown eccentrics are the major actuators for achieving strip flatness.Shiftable,first intermediate rolls are also shape actuators;they mainly serve for modifications in the strip edge area using a tapered roll profile. Measurement of mill geometry is available only indirectly through the rotation of the side and crown eccentrics and through the position of the first intermediate rolls. Consideration of mill spring and elastic deformation effects in the stack leads to the roll gap geometry.Accounting for mill spring and elastic deformation requires knowledge of the roll separating force which,in a closed 20-h mill,is measured indirectly through the adjustment pressure needed for the main side eccentrics.Apart from hysteresis effects,the effects of the variable geometry make this indirect measurement critical. Besides roll gap geometry,the task of presetting the mill also includes the design of pass schedules tailored to meet requirements of a product and the current mill condition.While optimal utilization of the mill is a major objective,the pass schedule must achieve the required produce quality.Generation of pass schedules to cover the statistical average and storing them in databases related to steel grade,surface and coil geometry is state of the art technology,In particular,mill parameters such as roll geometry or the thermal condition of the work rolls require dynamic correction of the pass schedules to obtain a reproducible final product.The same applies to variations in the material characteristics of the coils rolled. Because of the complexity of 20-hmills,achieving reproducibility of the final product quality and the optimum use of available mill resources to increase productivity represents an extremely difficult task.This task can be accomplished with a comprehensive model approach that takes all relevant mill and process parameters into account. To optimize the porcess,various mathematical models are needed to describe the elastic stand behavior and the elastic/plastic characteristics of the material to the rolled because neither direct geometrical information nor accurate roll force measurements exist. 1、 Force,torque and power The roll force,roll torque and drive power necessary to form the material are some of the most important items of process information.While power requirements affect the design of a pass schedule for optimal use of the available mill resources,roll force is mandatory for presetting the geometrical actuators.Both force and torque,on the other hand,need to be known for mill presetting so that mechanical or practical limits are not exceeded. The approach selected to describe the effects in the roll gap with regard to power,torque and force,is based on a strip fiber model using the basic theory developed by Karmanand Siebel.The roll gap model provides both vertical and tangential stress components acting on the work roll.The roll separating force results from the integration of the vertical pressure components.Torque and drive power are derived from the tangential stress. The roll gap model simultaneously provides accurate information about the vertical and tangential stress components acting on the roll and,thus,the drive power and roll force. The ability to evaluate the rolling process,based on accurate calculation of the roll separating force and main drive power,enhances,in particular,the material yield stress evaluation.This is beneficial since the roll force measurement is affected,to a large extent,by measurement hysteresis present in a closed 20-h mill. 2、 Material yield stress adaption Material yield stress adaption is required in any case where there is the need to roll a wide range of steel grades.Also,the demand for self-learning model algorithms forces the use of adaptive methods with regard to the yield stress. The yield stress of the material is initially evaluated in off-line tests using torsion bar samples.While off-line tests provide good initial information,each process and product has its own personality.This may result from the annealing practices or variations in the chemical composition of the steel grades. The yield stress adaption is broken down into a short-term adaption to rapidly adjust the yield stress curve,and a long-term adaption,where complex relationships between strain,strain rate and temperature are evaluated and represented. Statistical yield stress information is available by grade and also on an individ ual coil basis if needed,which improves quality assurance. 3、 Friction representation Besides obtaining a representation of the material yield stress,it isalso mandatory to describe the friction in the roll gap.In a variety of applications,the friction coefficient is adjusted so that during long-term analysis the most appropriate friction coefficient;ie,the coefficient that provides the best match between calculation and measurement,is applied. Another approach is to carry out rolling tests and analyze the results.While rolling tests affect production, the analysis method is time-consuming and may often have the disadvantage that not all relevant factors affecting friction are adequately considered.The approach selected in the current study is based on an artificial neural network. The entry layer of the neural network receives all relevant information as it has been gathered and may affect friction.This information is processed through the multilayer perceptron feed forward network in an off-line investigation using the back propagation method for training that,finally,leads to the friction coefficient.With a representative work,even physical relationships between the friction coefficient and process information can be evaluated. The results derived from the neural network have been used as the basis for an analytical model,which was implemented on-line. The accuracy of the representation has been evaluated in several on-line rolling tests in industrial facilities.Since mill speed is one of the main variables affecting friction,one pass was made during the commissioning phase of the model with different mill speeds.Both the measured and calculated roll force were recorded. Apart from the friction coefficient,both the temperature of the strip approaching the roll bite and the strain varied in the test. 4、 Elastic mill stand behavior In addition to roll force,power and torque,the elastic behavior of the mill stand must also be described to allow propagation from the measured eccentric adjustments to the roll bite contour,which is the target for further optimization steps. One requirement in the elastic mill stand model was its ability to cover a variety of different mill configurations,roll profiles and roll materials.These variables were also specified with respect to each individual roll in the stack to cover situations where unusual roll combinations are selected and to allow the model to be used during design phases. To provide maximum flexibility,the description of the elastic mill stand behavior is based on a numerical solution approach for the roll stack.The different effects,such as flattening between the rolls,flattening between the strip and the work rolls,and deflection of the several rolls,are derived from multiple iterations. The elastic mill stand model for the 20-h cold rolling mill can,generally,be divided into two parts.The initial phase involves a rapid determination of the load share in the second phase.The initial load share derived is then taken,in the second phase,as basis for the iterative determination of the interaction between load distribution,flattening and deflection. The deflection of each roll is derived from the load distribution determined in each iteration step.The geometrical differences between neighboring rolls are interpreted as flattening of the rolls for which a certain load distribution must be present.This leads to a new load along the contact area of the various rolls.This new load distribution leads,again,to a new deflection. The total effect of elastic deformation between the rolls produces a new load at the saddle segments of the backup rolls.Thus,the mill spring appears to be different,and a new iteration needs to be performed.The iteration is carried out until a solution has been reached,where the entire load,the deflection and flattening match. 5、 Summary The accuracy of force measurement in a closed sendzimir mill is inadequate for high-precision process control.To solve this problem,special model for determination of roll force and roll torque has been developed.The tangential and vertical stress components acting on the work rolls are described to permit the calculation for yield stress adaptions based on the power consumption of the main drive. A model has been developed that describes the elastic mill stand behavior and considers the interaction of roll deflection with load distribution and roll flattening.The model represents a multiple iterative solution approach. 建模与优化为 20 - H的冷连轧 质量和可重复性是其主导的标准，冷轧 products.in ，特别是高带钢表面质量能达到与轧机特别安排，如 20小时 mill.this类型的用途，小轧机工 作辊在接触带，即是存放在地方与不同的中间和备份 rolls.the使用不同的驱动器，在部分中，只有法，间接影响到轧辊咬几何，使预设的轧机方面带的厚度和平整度是一项复杂的任务。 本文介绍了模型的目的是优化整个轧制过程在 20小时 mill.results获得来自数个上线应用的讨论。 一个封闭的 sendzimirmill的安排，显示在图 1 ，说明的主要动影响轧辊咬几何方面带的厚度和 glatness.side eccentrics位于备份卷是用来调节整体的立场，相应的辊轴较广泛范围内，间接，调整辊缝几何方 面向 millpassline带thickness.side eccentrics可能是机械或电动 coupled.crown eccentrics可在几个地点超过每桶 length.those ，通常是在上备份卷，有能力提供特别辊缝 contours.they匹配的差距概况带进入 mill.crown eccentrics是主要的致动器实现带 flatness.shiftable ，第一中间辊也形成动，他们主要是为修改，在带边缘区使用锥形辊。 测量轧机几何只可间接透过旋转的一侧和官方 eccentrics并通过的立场，第一中间辊。 审议轧机春季和弹性变形的影响，在堆栈，导致登记册上的差距geometry.accounting轧机春季和弹性变形，需要知识的轧辊分离力，在一个封闭的 20 - H的轧机，是衡量间接透过调整的压力，需要为主要方 eccentrics.apart从滞后效应，影响的可变几何使这个间接测量的关键。 此外辊缝几何，任务预轧机，还包括设计通过附表定制，以满足要求的产品，以及目前轧机 condition.while最佳利用轧机是一个重大的目标，通过附表必须达到规定的生产 quality.generation的通行证附表涵盖统计平均，并把它们保存在数据库相关的钢级，地表水和线圈几何是国家的最先进的技术，特别是轧机参数，如轧辊几何或热条件下的工作辊要求动态修正的通过附表取得重现最后产品的同样适用于不同的材料特性的线圈推出。 因为复杂 20 - hmills ，实现重复性的最终产品的质量和最佳利用现有轧机资源，以增加生产力，代表了一个极端困难的 task.this的任务可以完成一个全面的模型方法，考虑所有相关的磨和过程参数在内。 优化 porcess ，各种数学模型需要来形容 弹性的立场，行为和弹性 /塑料的特性的材料轧制，因为没有直接的几何信息，也没有准确的轧辊力的测量存在。 1.武力，扭矩和功率 轧辊武力，滚转力矩和驱动力要形成的物质是一些最重要的项目进程information.while电力需求影响的设计，合格的时间表，优化利用现有的资源，轧机，轧辊的力量是强制性的为预设几何 actuators.both武力和扭矩，另一方面，需要被称为轧机预设，使机械或实际限制是不得超过。 选定来形容的影响，在辊缝方面的权力，扭矩和力量，是基于一个带纤维模型使用的基本理论研 制的 karmanand siebel.the辊缝模型提供纵向和切向应力分量作用于工作 roll.the轧辊分离力的结果，从一体化的垂直压力components.torque和驱动力是来自切向应力。 该辊缝模型，同时提供准确的资料，有关垂直和切向应力分量署理对轧辊，因此，驱动电源和轧辊的力量。 能力评价轧制工艺的基础上，精确计算轧辊分离力和主要驱动力，增强了，特别是材料的屈服应力 evaluation.this是有利的自辊测力受到影响，相当大的程度上，由测量滞后，目前在一个封闭的 20 - H的轧机。 2.材料的屈服应力适应性 材料的屈服应力适应是需要在任何情况下，是有需要推出广泛的钢grades.also ，要求自学模型算法势力利用自适应方法方面的屈服应力。 屈服应力的材料是初步评估，在离线测试使用扭杆 samples.while脱线测试，提供了良好的初步资料，每个过程和产品都有自己的 personality.this可能会导致从退火的做法或变化的化学组成钢职系。 屈服应力适应细分为短期的适应迅速调整屈服应力曲线，和长期的适应，之间的复杂关系应变，应变速率和温度的评价，并代表。统计屈服 应力所得的资料，按职等和还就