钢轨万能精轧过程的三维弹塑性有限元模拟

借助有限元分析软件MSC.Marc,采用三维热-机耦合弹塑性有限元模型,对钢轨万能精轧过程进行模拟分析。以UR-EF-UF三机架连轧过程为研究对象,建立变形过程优化模型。将轧件尺寸模拟结果与实验结果进行比较,两者吻合较好,验证了模型的准确性。对轧件变形过程、轧制接触状态、应力应变分布以及速度变化等模拟结果进行了讨论分析,揭示了万能轧机各道次的加工特点和轧件在连轧变形过程的变形规律。     

60 kg/m钢轨万能轧制过程有限元模拟研究

以鞍钢大型厂60 kg/m钢轨轧制过程为研究对象,通过MSC.Marc软件,建立三维弹塑性热-机耦合有限元模型,模拟分析了万能轧机轧制生产过程中轧件的变形和受力情况。模拟结果与实际结果吻合较好,应用所建立的有限元模型对万能轧制机组轧制过程进行模拟,获得了轧制过程轧件变形、受力以及速度等参数的分布情况。     

Analysis of Metal Forming in Two-Roll Cross Wedge Rolling Process Using Finite Element Method

A simulation model for two-roll cross wedge rolling (CWR) was presented by using three-dimensional rigid-plastic finite element method (FEM).The whole forming process of CWR,including knifing zone,guiding zone,stretching zone,and sizing zone,was simulated using the model in which dynamic adaptive remeshing technology for tetrahedral solid elements was used to fix element distortion.Based on the simulation results,the distributions of metal flow field,strain field,and damage field,and the geometry of the workpiece's end were analyzed.These results could provide theoretical guidance for realizing net shaping and reasonable design of tools.     

车轮轧制成形过程有限元分析

使用MSC.SuperForm对840火车轮轧制成形过程建立三维热力耦合有限元分析模型,研究分析了车轮立式轧制成形过程的金属变形规律.得出车轮轧制成形过程最大变形分布在辐板与轮辋连接处及轮辋外端靠近踏面处,轮辋外端变形明显大于轮辋内端变形,轮辋中心变形较难深透;车轮轧制中,辐板靠近轮辋端的金属周向流动明显,周向流动主要发生在轧制中后期;研究还得出车轮轧制过程各轧辊的受力及其变化情况,为制定车轮轧制工艺提供了参考.     

基于ANSYS的2150mm万能轧机机架模态分析

利用有限元软件ANSYS建立2150 mm万能轧机机架有限元模型,并对其进行模态分析,分别得出万能轧机主机架和立辊机架前15阶固有频率及振型图;通过振型图可直观分析出主机架与立辊机架的动态特性以及对实际生产影响最大的固有频率,为万能轧机的结构设计提供直接的理论依据。     

Nonlinear Finite Element Analysis of Thin Strip Temper Rolling Process

 To reveal the basic deformation mechanisms under the conditions of high friction, small reduction, and long contact length in thin strip temper rolling process, an elastoplastic finite element analysis of plane strain upsetting was made based on the FEM software Marc. The results indicated that a near flat ‘zero reduction’ region was present in the center of the contact arc. The simulation results about the effect of rolling parameters on the central flat region showed that any change of increasing the rolling force could result in or enlarge the central flat region in the deformation zone. Stress distribution results illustrated that the metal was in triaxial compression state. Although the maximum and minimum principal stresses were all much larger than the yield stress of the strip, the equivalent stress became lower than that, and no further plastic strain, even a small elastic spring back occurred in the central flat region. That was the problem of ‘hydrostatic pressure’ in thin strip temper rolling.     

Recalculation of Flow Stresses from Industrial Process Data for Heavy Plate Rolling Using a 2D Finite Element Model

In hot rolling, the quantities rolling load, torque, and power consumption are important measurable process parameters. For the determination of rolling loads in hot flat rolling processes, like heavy plate rolling, Sims's model 1 is a well‐known approach represented by an analytical formula. The solution of Sims's equation leads to the multiplier Q, which is a function of the roll gap geometry. The rolling load is then computed by applying the width of the plate, the contact length, the multiplier, and an average material flow stress called k_fm. This flow stress is commonly recalculated from process data as a function of temperature, pass strain, and a mean strain rate, applying the Sims model itself. One question arises from this method: Are the recalculated flow stresses physically based values or in other words, what is the (physical) meaning or interpretation of these values? The present paper tries to give an answer to this question by determining the influence of the roll gap geometry alternatively by means of a simple 2D FEM model which gives a corresponding multiplier referred to as Q_FE. Flow stresses are recalculated from a set of process data using both factors. The results are compared to experimental flow stress data from hot compression tests. It is shown, that the recalculated flow stresses using Q_FE are in better agreement with the laboratory data than the recalculated values using Sims's Q.     

小型H型钢粗轧过程数值模拟及翼缘宽展分析

运用有限元方法对4种规格小型H型钢的粗轧过程进行了三维热力耦合数值模拟,详细介绍了有限元模型和模拟参数设置。在数值模拟结果的基础上,分析了小型H型钢各道次稳定轧制阶段的孔型填充状况、有效塑性应变和翼缘宽展规律。根据推导的小型H型钢斜配孔型翼缘宽展公式计算了各道次翼缘高度解析结果,并将翼缘高度解析结果、数值模拟结果和实测结果进行了对比,规律性吻合较好。     

十字轴的有限元分析

针对1549mm轧机十字轴式万向联接轴的十字轴进行有限元分析,找出了十字轴的位移、应力分布规律,并对在均布载荷、三角形分布载荷两种工况下的计算结果进行了比较.     

Modelling a Skin-Pass Rolling Process by Means of Data Mining Techniques and Finite Element Method

 An experience is presented using the finite element method (FEM) and data mining (DM) techniques to develop models that can be used to optimize the skin-pass rolling process based on its operating conditions. A FE model based on a real skin-pass process is built and validated. Based on this model, a group of FE models is simulated with different adjustment parameters and with different materials for the sheet; both variables are chosen from pre-set ranges. From all FE model simulations, a database is generated; this database is made up of the above mentioned adjustment parameters, sheet properties and the variables of the process arising from the simulation of the model. Various types of data mining algorithms are used to develop predictive models for each of the variables of the process. The best predictive models can be used to predict experimentally hard-to-measure variables (internal stresses, internal strains, etc) which are useful in the optimal design of the process or to be applied in real time control systems of a skin-pass process in-plant.     

双机架紧凑式可逆炉卷轧机板材热连轧的温度场有限元研究

本文实现了对国内唯一一架双机架紧凑式可逆炉卷轧机板材热连轧的温度场有限元研究。采用弹塑性大变形热力耦合有限元法研究板材热连轧过程。利用有限元理论建立了板材热连轧模型,应用MSC／MARC软件进行计算,重点分析了轧制过程和变形区中轧件的温度场分布和变化。计算结果与实际生产情况相吻合,同时表明有限元理论可以实现对板材热连轧过程的数值模拟。     

H型钢轧制过程三维弹塑性大变形有限元模拟

针对轧制Ｈ型钢过程中易出现产品缺陷等问题,应用有限元软件（ＭＡＲＣ）的二次开发技术建立了Ｈ型钢的轧制模型,模拟了轧制过程。给出了Ｈ型钢的腹板、翼缘及其交界区３点在轧制过程中的应力及金属流动变化情况。结果表明,轧件出口后轧制断面上轧制方向的残余应力是造成Ｈ型钢腹板屈曲及其他缺陷的主要原因     

带材异步冷轧时大变形弹塑性有限元模拟和实验

采用纠正的拉格朗日列式和基于弹塑性乘法分解的超弹性－塑性本构关系建立了大变形弹塑性有限元程序，并对铝带在不同条件下的异步冷轧过程进行数值模拟，同时对计算结果进行实验验证。结果表明，在异步轧制时，轧制压力对工作辊辊径的变化表现出非敏感性，而且变形区内静水压力绝对值比同步轧制时要小得多。     

刚塑性有限元解题法的改进及在轧制中的应用

本文对刚塑性有限元的初速度场及收敛性进行了专门的研究和改进。用于解决轧制工程问题,计算精度较高、CPU时间较少,它是一种可靠的理论分析方法。     

轧机主传动系统动态特性有限元分析

针对轧机传动系统因负荷突变而引起的扭振现象,建立了轧机有限元模型,进行有限元模态分析和谐响应分析,找出了相应措施来减少轧机的振动,从而降低破坏概率,延长了设备寿命。     

Theoretical and Experimental Research on the Rolling Force in Rail Hot Rolling by Universal Mill

 In rail rolling by universal mill, a simplified 3-dimention theoretical model has been built firstly. The kinematically admissible velocity field of the web, head and base of rail have been determined respectively, moreover the corresponding strain rate field and the strength of shear strain rate have been also obtained. Then the plastic deformation power of corresponding deformation zone, the powers consumed on the velocity discontinuity surface and the powers generated for backward slip and forward slip have been proposed. According to the upper-bound method, the roll force of horizontal roll and two vertical rolls can be obtained. Moreover, The process of 18kg/m light rail and 60kg/m heavy rail universal rolling have been simulated by rigid-plastic FEM(finite element method) for verifying the theoretical model. And the universal rolling experiments of 18kg/m light rail has been accomplished in Yanshan University Rolling Laboratory. Compared the results of numerical simulation and the experimental data, the roll force from upper-bound method is somewhat greater than experimental data but in general do not exceed them by 20 percent. So, it is reliable and feasible to preset and optimize the parameter of rolling technology according to the upper-bound method.     

A Newly Developed Upper‐Bound Approach for Calculating the Width Flow in Hot Rolling

This paper presents an investigation of the 3D metal‐forming process during hot flat rolling by an upper‐bound approach. The general aspects of this limit analysis refer to the volume deformation taking into account a polynomial propagation of the free side surfaces. In this approach the deformation region is limited by the roll‐gap entrance and exit with parallel planes. It is characterized by a non‐linear velocity field. A mathematical model of an upper‐bound calculation for the symmetrical flat rolling is developed in order to examine the influence of the most relevant functions, namely the velocity field together with the boundary conditions. A comparison of reasonable onsets is proposed. Therefore, the study can offer useful knowledge for better prediction of lateral flow.     

可逆式轧机十字轴式万向联轴器辊端叉头的有限元分析

运用ANSYS程序对辊端叉头进行三维有限元分析 ,找出其危险部位 ,确定其能长期承受的扭矩和短时能承受的最大扭矩。并对辊端叉头的结构和维护提出改进意见。