厚壁管斜轧穿孔顶杆失稳控制方法研究

发布时间：2018-04-20 05:21

本文选题：厚壁管 + 斜轧穿孔　；参考：《西安建筑科技大学》2017年硕士论文

【摘要】：在斜轧穿孔过程中,轧辊对于管坯的作用力会沿轧制线的方向传递到顶头及顶杆上。当此轴向力过大时,会导致顶杆失稳发生弯曲,从而使轧制出来的钢管发生弯曲变形。为了防止这种情况的发生,则需要安装定心装置来保证毛管轴线和轧制中心线保持一致,确保顶杆在轧制过程中具有较高的稳定性。同时,会降低顶头和顶杆的消耗,提高生产作业率。然而现有的斜轧穿孔机出口装置定心辊的位置是均匀布置的,定心辊的安装位置与顶杆的实际失稳位置不一致,进而引起失稳防控能力低并增加不必要的设备投资及维修费用。针对上述问题,本文采用理论分析以及有限元模拟方法对顶杆定心辊安装位置以及失稳控制效果进行研究分析,主要研究内容和分析如下:根据压杆失稳力学分析建立了u及ω的模型,对顶杆的失稳位置和弯曲挠度值进行分析计算,确定顶杆的失稳条件、失稳位置以及定心装置的布置形式。计算分析表明:顶杆的失稳危险点是非对称的,一般10~12m长的顶杆,从顶杆尾端至顶头端的排布位置依次是:采用ABAQUS有限元模拟软件建立顶杆受力弯曲模型,模拟不同因素在非均布定心装置与均布定心装置条件下对顶杆失稳弯曲过程的影响。模拟结果表明:顶杆一端固定一端铰支时的失稳危险点在距离固定端2/3L处,非均布定心装置比均布定心装置的防控效果好。在Φ240mm二辊斜轧穿孔机设备条件下,模拟了顶杆受力的弯曲过程。用ABAQUS软件结合实际顶杆受力情况建立有限元模型,模拟了不同因素对顶杆临界失稳力、最大挠度值以及等效应力的影响。模拟结果表明:随着顶杆直径的增加,临界失稳力增加,弯曲的最大挠度值减小,等效应力增加;随着顶杆长度的增加,失稳临界力减小,弯曲的最大挠度值增加,等效应力增加。在1600KN四柱液压机设备条件下,进行顶杆受力弯曲的试验检验。试验结果表明:顶杆受力弯曲后的失稳位置均在距离顶杆固定端2/3处,弯曲时所受轴向力、挠度值的变化趋势与理论计算及模拟结果相符。然而,由于试验条件受到限制,试验并不是在理想状态下进行的,导致挠度值与理论计算及模拟结果之间存在一定的误差,但误差都在±10%以内。
[Abstract]:In the process of cross-rolling piercing, the force of roll on tube billet will be transferred to the top and top rod along the rolling line. When the axial force is too large, the buckling of the jacking rod will occur and the rolled steel tube will bend and deform. In order to prevent this from happening, it is necessary to install a centering device to ensure the consistency between the capillary axis and the rolling centerline, and to ensure the high stability of the top rod in the rolling process. At the same time, it will reduce the head and rod consumption, improve the production rate. However, the position of the centering roller of the outlet device of the existing cross-rolling piercer is uniformly arranged, and the installation position of the centering roller is not consistent with the actual unstable position of the top rod, which leads to the low capability of instability prevention and control and increases the unnecessary equipment investment and maintenance cost. In order to solve the above problems, theoretical analysis and finite element simulation method are used to study the installation position and instability control effect of the centering roller. The main research contents and analysis are as follows: according to the analysis of the buckling mechanics of the pressure-rod, the models of u and 蠅 are established, and the unstable position and bending deflection of the jacking rod are analyzed and calculated, and the instability conditions of the jacking rod are determined. The unstable position and the arrangement of the centering device. The calculation and analysis show that the dangerous point of instability of the top rod is asymmetrical. The arrangement position from the end of the top rod to the end of the head of the top rod is in the order of 10 ~ 12m long. The bending model of the force of the top rod is established by using ABAQUS finite element simulation software. The influence of different factors on the buckling process of the rod under the condition of non-uniform centring device and homogenizing centering device was simulated. The simulation results show that the unsteady danger point of one end hinge support is 2 / 3 L from the fixed end, and the control effect of the non-uniform centring device is better than that of the uniform centring device. Under the condition of 桅 240mm two-roll cross-rolling piercing machine, the bending process of the force acting on the top rod is simulated. The finite element model is established by using ABAQUS software combined with the actual force of the jacking rod. The effects of different factors on the critical instability force, maximum deflection value and equivalent stress of the jacking rod are simulated. The simulation results show that with the increase of the diameter of the rod, the critical instability force increases, the maximum deflection of the bending decreases and the equivalent stress increases, and with the increase of the length of the top rod, the critical force decreases and the maximum deflection of the bending increases. The equivalent stress increases. Under the condition of 1600KN four-column hydraulic press equipment, the force bending test of the top rod is carried out. The experimental results show that the position of instability of the top rod after bending is 2 / 3 from the fixed end of the top rod. The variation trend of axial force and deflection value is consistent with the theoretical calculation and simulation results. However, due to the limitation of the test conditions, the test is not carried out in ideal condition, which leads to a certain error between the deflection value and the theoretical calculation and simulation results, but the error is within 卤10%.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG333.8

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