Variable gauge rolling （VGR） is a new technology to produce flat products with different thicknesses （FDT）, which could be used to replace conventional fiat products in order to save metals and reduce structure ma...Variable gauge rolling （VGR） is a new technology to produce flat products with different thicknesses （FDT）, which could be used to replace conventional fiat products in order to save metals and reduce structure mass. The method of VGR was introduced for investigating new problems in rolling theory of VGR, and the new formulas for calculating parameters of VGR were proposed. Besides, some results of numerical simulation by finite elemen~ method were described. As an example, the products applications of FDT in bridge construction, ship building and auto manufacturing were presented. Finally, the prospects for VGR and FDT were discussed.展开更多
Variable gauge rolling （VGR） is a new technology for producing the materials which have the advantage of lightweight due to optimized thickness according to load distribution. The new progresses in the theoretical r...Variable gauge rolling （VGR） is a new technology for producing the materials which have the advantage of lightweight due to optimized thickness according to load distribution. The new progresses in the theoretical research and application of VGR are reviewed in this paper. Two basic equations, VGR-f and VGR-s, were deduced. The former is a new differential equation of force equilibrium, and the latter is a new form of formula for the law of mass conservation. Both of them provide a new base for the development of VGR analysis. As the examples of VGR＇s application, tailor rolled blank （TRB） and longitudinal profile （LP） plate are introduced. Now TRBs are only produced in Germany and China, and have been used in the automotive manufacturing to play an important role in lightweight design. LP plates have been used in shipbuilding and bridge construction, and promised a bright prospect in reducing construction weight. In addition, new technologies and applications of VGR emerge constantly. Tailor welded strips and tailor rolled strips with variable thickness across the width can be used for progressive die and roll forming. The 3D profiled blank can be obtained by two-step rolling process. Tailor tubes witli the variable wail thickness are an efficient way to reduce the weight. The blank with tailored thickness and mechanical property is also under development. Above products based on the tailored ideas provide a new materials-warehouse for the designers to select so as to meet the needs of weight reducing and material saving.展开更多
Within the production chain of longitudinal profiled （LP） plates and tailor rolled blanks （TRB）, variable gauge roiling （VGR） represents the vital important forming stage, in which shape and properties are tailo...Within the production chain of longitudinal profiled （LP） plates and tailor rolled blanks （TRB）, variable gauge roiling （VGR） represents the vital important forming stage, in which shape and properties are tailored to sat- isfy customers＇ requirements. It is of vital importance to reveal the relationship between work-piece horizontal veloci- ty and roll vertical velocity during VGR, which is not only a key point to understand the deformation law, but also an important content for setting VGR process parameters. It is proved that the simplified assumption of equal dis- charge per second condition （EDSC） breaks down during VGR. Due to this reason the differential equation of the work-piece horizontal velocity （VGR-V） is performed by keeping the material volume constant. To attain a compre- hensive understanding of this underlying process in detail, numerical approaches based on finite elements method have been performed by utilizing the Abaqus Explicit. Rolling experiment is carried out which indicates that the nu- merical result coincides with the expel＇imental result well. A fine spatial discretization of work-piece is essential for special emphasis has to be put on detecting different horizontal velocity of work-piece cross section, often leading to a hundred thousand degrees of freedom even for plane strain calculations. The data obtained by using Abaqus Explicit coincide with the results determined by theory. A theoretical basis on deformation parameters and mechanical param- eters during VGR process is provided.展开更多
The vertical motion control of the roll was studied in order to improve the accuracy in simulation of variable gauge rolling. The discretization was carried out in the transition zone of TRB according to the principle...The vertical motion control of the roll was studied in order to improve the accuracy in simulation of variable gauge rolling. The discretization was carried out in the transition zone of TRB according to the principle of volume invariance. Based on this assumption, the formula for time step of vertical motion of rolls was proposed and the time-displacement curve of the verti- cal motion of rolls was established. In the preliminary simulation, the time-displacement curve was used as an initial method to control the vertical motion of rolls. Based on the simulation result, the formula for vertical velocity of roll in variable gauge rolling was derived from the common rolling principle. According to the formula, reasonable vertical velocity of rolls in the subsequent simulation was determined. It can accurately control the motion of rolls along the vertical direction. The desired thickness and out- line profile of transition zone were acquired and the formula proved effective by the simulation. Further analysis shows that the di fference of thickness in the thick zone and the thin zone of TRB, length of the transition zone of TRB, radius of work rolls and rota- tion speed of rolls have a significant effect on the vertical velocity of rolls.展开更多
基金Item Sponsored by National Natural Science Foundation of China(50634030,50974039)
文摘Variable gauge rolling （VGR） is a new technology to produce flat products with different thicknesses （FDT）, which could be used to replace conventional fiat products in order to save metals and reduce structure mass. The method of VGR was introduced for investigating new problems in rolling theory of VGR, and the new formulas for calculating parameters of VGR were proposed. Besides, some results of numerical simulation by finite elemen~ method were described. As an example, the products applications of FDT in bridge construction, ship building and auto manufacturing were presented. Finally, the prospects for VGR and FDT were discussed.
基金supported by the National Natural Science Foundation of China (Nos. 51034009, 51374069 and 51174249).
文摘Variable gauge rolling （VGR） is a new technology for producing the materials which have the advantage of lightweight due to optimized thickness according to load distribution. The new progresses in the theoretical research and application of VGR are reviewed in this paper. Two basic equations, VGR-f and VGR-s, were deduced. The former is a new differential equation of force equilibrium, and the latter is a new form of formula for the law of mass conservation. Both of them provide a new base for the development of VGR analysis. As the examples of VGR＇s application, tailor rolled blank （TRB） and longitudinal profile （LP） plate are introduced. Now TRBs are only produced in Germany and China, and have been used in the automotive manufacturing to play an important role in lightweight design. LP plates have been used in shipbuilding and bridge construction, and promised a bright prospect in reducing construction weight. In addition, new technologies and applications of VGR emerge constantly. Tailor welded strips and tailor rolled strips with variable thickness across the width can be used for progressive die and roll forming. The 3D profiled blank can be obtained by two-step rolling process. Tailor tubes witli the variable wail thickness are an efficient way to reduce the weight. The blank with tailored thickness and mechanical property is also under development. Above products based on the tailored ideas provide a new materials-warehouse for the designers to select so as to meet the needs of weight reducing and material saving.
基金Item Sponsored by National Natural Science Foundation of China(51174249,50974039)
文摘Within the production chain of longitudinal profiled （LP） plates and tailor rolled blanks （TRB）, variable gauge roiling （VGR） represents the vital important forming stage, in which shape and properties are tailored to sat- isfy customers＇ requirements. It is of vital importance to reveal the relationship between work-piece horizontal veloci- ty and roll vertical velocity during VGR, which is not only a key point to understand the deformation law, but also an important content for setting VGR process parameters. It is proved that the simplified assumption of equal dis- charge per second condition （EDSC） breaks down during VGR. Due to this reason the differential equation of the work-piece horizontal velocity （VGR-V） is performed by keeping the material volume constant. To attain a compre- hensive understanding of this underlying process in detail, numerical approaches based on finite elements method have been performed by utilizing the Abaqus Explicit. Rolling experiment is carried out which indicates that the nu- merical result coincides with the expel＇imental result well. A fine spatial discretization of work-piece is essential for special emphasis has to be put on detecting different horizontal velocity of work-piece cross section, often leading to a hundred thousand degrees of freedom even for plane strain calculations. The data obtained by using Abaqus Explicit coincide with the results determined by theory. A theoretical basis on deformation parameters and mechanical param- eters during VGR process is provided.
基金Sponsored by Natural Science Foundation of CQ CSTC of China(cstc2012jj A70001)
文摘The vertical motion control of the roll was studied in order to improve the accuracy in simulation of variable gauge rolling. The discretization was carried out in the transition zone of TRB according to the principle of volume invariance. Based on this assumption, the formula for time step of vertical motion of rolls was proposed and the time-displacement curve of the verti- cal motion of rolls was established. In the preliminary simulation, the time-displacement curve was used as an initial method to control the vertical motion of rolls. Based on the simulation result, the formula for vertical velocity of roll in variable gauge rolling was derived from the common rolling principle. According to the formula, reasonable vertical velocity of rolls in the subsequent simulation was determined. It can accurately control the motion of rolls along the vertical direction. The desired thickness and out- line profile of transition zone were acquired and the formula proved effective by the simulation. Further analysis shows that the di fference of thickness in the thick zone and the thin zone of TRB, length of the transition zone of TRB, radius of work rolls and rota- tion speed of rolls have a significant effect on the vertical velocity of rolls.
文摘为实现高精度的变厚度轧制,需要对变厚度轧制的厚度控制模型进行研究.基于离散化的控制思想和轧制弹跳方程建立了一种TRB变厚度区轧制辊缝设定模型,用于单机架可逆式四辊冷轧机厚度控制系统.研究了辊缝变化的非线性规律,基于误差分析提出了确定离散区间的方法;给出了一种TRB辊缝控制系统结构以及空载辊缝闭环和负载辊缝闭环的控制方程,并在实验四辊轧机上进行了单厚度过渡区的TRB轧制.结果表明,采用离散化的辊缝设定方法可以实现TRB板的50 mm变厚度区,尺寸最大厚度偏差为0.08 mm,长度偏差<1 mm.
