共查询到18条相似文献,搜索用时 640 毫秒
1.
为了研究带钢局部高点卷取过程起筋的控制方法,基于应力函数假设和S Timoshenko最小功原理获得了起筋带钢的应力场分布,并采用伽辽金虚位移原理建立了可用于在线计算的起筋临界卷取张力设定模型和起筋弹性极限模型。并对应力场分布和临界卷取张力各影响因素进行仿真研究,仿真结果表明:局部高点在径向累积叠加所引起的带钢张力不均匀分布和轴向压应力是导致带钢起筋的主要原因;临界卷取张力随带钢厚度、局部高点高度和卷取半径增大而减小,带钢宽度对钢卷的起筋临界卷取张力影响非常小。通过与实际生产控制方法和ANSYS有限元分析结果对比,验证了本模型的计算精度和可行性。 相似文献
2.
3.
4.
5.
对热轧带钢在冷轧过程中产生的"起筋"缺陷进行了分析.通过大量统计数据,分析了"起筋"位置、成因、"起筋"卷局部高点、凸度以及楔形之间的关系,并对热轧工艺进行了改进,取得了很好的效果,保证了断面适当的大凸度、小楔形和适当的局部高点,大大降低了带钢"起筋"率,改善了产品质量. 相似文献
6.
7.
针对热轧带钢在下工序冷轧过程中出现的起筋现象,从热轧角度进行分析,从冷轧带钢起筋位置分析出与热轧带钢断面局部高点、凸度和楔形之间的对应关系.通过对热轧工艺参数的调整,实现了带钢断面大凸度、小楔形和适当的局部高点,减少了冷轧带钢起筋现象,改善了产品质量. 相似文献
8.
简要介绍了卷取带钢头部和尾部过程中助卷辊的踏步控制功能所起的作用.针对卷取机张力建立后助卷辊摆开的自动控制进行了详细介绍,助卷辊协助芯轴控制带钢头部建立张力,张力建立之后,助卷辊自动摆开到最大位,保证带卷边部整齐. 相似文献
9.
为了明确6辊矫直机在不同工况下张力变化规律,进而有效提出矫直策略,利用ABAQUS弹塑性有限元软件,以某厂6辊张力矫直机为仿真对象,建立了带钢矫直过程的二维弹塑性仿真。通过大量不同工况下的仿真分析,探索带钢出口张应力与工艺设定辊缝值的大小、入口张应力、待矫直带钢的带钢厚度和屈服强度的关系。结果表明,带钢出入口张力比随总辊缝、屈服强度、厚度的增加而线性增大,随入口张应力的增大而减小。本工作可优化矫直工艺参数,为提高矫直效率奠定理论基础与应用指导思路。 相似文献
10.
热连轧钢卷卷取过程摩擦力与位移场分布的研究 总被引:1,自引:0,他引:1
为了分析热轧带钢在卷取过程中层间摩擦力分布和确定卷筒胀径时最小带卷层数,利用有限元的手段再现了热轧带钢卷取的全过程.在热轧带钢厚度为5~20 mm和带卷层数为2~5层的基础上,研究了卷筒胀径过程中热轧带钢层间和最内层节点金属的流动规律,提出了以热轧带钢头部相对位移的大小为判据,获得了胀径过程热轧带钢不发生松卷的条件.研究结果表明:摩擦力分布和胀径时热轧带钢的层数有关,当热轧带钢卷取到第5层时卷筒进行胀径可建立稳定的卷取状态.研究成果对提高热轧带钢卷取的产量和减少助卷辊的磨损有一定的指导意义. 相似文献
11.
12.
Incoldstriproling,thetransversedistributionoftensionstressisadecisivefactorofstripshape.Largenon-uniformtensionstressdistribu... 相似文献
13.
基于ABAQUS有限元软件建立了薄带材浪形生成与拉伸过程有限元模型,研究了带材在初应变作用下的浪形缺陷生成规律及其在张力拉伸作用下的应力特性及其变形行为,并进一步分析了浪形缺陷拉伸矫直矫平功效的主要影响因素及其影响规律.薄带钢变形过程可分为浪形生缺陷生成、拉伸矫直和弹性回复三个阶段.针对薄钢带弹性后屈曲浪形和铝带弹塑性后屈曲浪形两类典型浪形形式,研究了浪形缺陷在后屈曲和拉伸变形阶段的浪形陡度变化与系统能量变化规律.研究表明:弹性后屈曲浪形在拉伸矫直过程中浪数和浪高均发生变化,而弹塑性后屈曲浪形仅发生浪高的连续变化.弹性后屈曲浪形矫直后的残余应力分布形式与初始应力分布类似,而弹塑性后屈曲浪形的残余应力分布发生显著差异.浪形缺陷的残余陡度随初始浪形陡度增大而增大,随带厚增加而减小,且弹塑性后屈曲浪形缺陷的矫直效果更为显著. 相似文献
14.
15.
Modeling of Stress Distribution During Strip Coiling Process 总被引:1,自引:0,他引:1
Many strip materials are coiled after rolling process. The stresses are imposed on the material wound on the automatically controlled collapse mandrel under the coiling tension. The coiling process can be described by three typical cases: winding without automatic adjustment, winding with automatic adjustment and after mandrel removal. A new model of equations for predicting the stresses during the strip coiling process is built by consideration of the three cases respectively. By solving the equations of different typical cases, the radial stresses and tangential stress of the layers of coil can be calculated. Also, the coiling parameters, such as strip thickness, coiling tension and necking critical pressure, affecting the coil performance are investigated. It is believed that the present model can be used for design and control of the automatically controlled collapse mandrel. 相似文献
16.
During and after rolling or flattening of metal strips and plates the permissible deviations from flatness are described by the permissible absolute wave height and the flatness index. Both values can be determined on a measuring table while the material is not subjected to global tension. Because this procedure is expensive, time‐consuming and allows measurement only at discrete positions along the strip length, on‐line flatness measuring systems are used which can detect the distribution of longitudinal tensile stresses distributed across the strip width allowing for the calculation of the flatness index. This value does not always agree with the value obtained directly by measuring on the table even when the measurement of the longitudinal tensile stress distribution operates perfectly. It can be shown that the measurement of the tensile stress distribution does not give a direct indication on the wave height in the tension‐free state determined on the measuring table. To explain the relationship between tensile stress distribution in the strip and the flatness measurement on the measuring table, the buckling behavior is analysed both with and without dead load for simple symmetrical residual stress distributions resulting, e.g., from the rolling process. Based on the knowledge of the distribution of the longitudinal residual stresses across the strip width, the flatness index and the wave height can be determined by using a specialized finite element model. If the direct measurement is performed under action of dead load, large differences between the directly and indirectly obtained flatness index are observed. Below a certain limit of the intensity of the residual stress distribution the strips and plates lie flat on the measuring table. Above this limit the strip lying on the table exhibits post‐bucking deformations. In the latter case, the wave height increases with strip thickness and intensity of residual stresses. 相似文献
17.