共查询到19条相似文献,搜索用时 281 毫秒
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采用ANSYS/LS—DYNA有限元软件模拟计算了中厚板生产中轧机前后辊道在轧件头部平直、头部弯曲、轧件已离开轧机、轧件未离开轧机等不同情况下所受冲击载荷的等效应力,得出在轧件已离开轧机情况下,与辊道发生对心碰撞时辊道所受应力最大;在未抛钢情况下,辊道所受应力远大于前者,且在轧件头部下弯量达60mm时,辊道所受应力已超出其材料许用应力。 相似文献
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中厚板平面形状变形规律及其测定的研究 总被引:3,自引:0,他引:3
论述了中厚板在轧制过程中的平面形状变形行为,阐述了用合成照相法定量确定中厚板平面形状的原理和测定方法。并用铅试样进行了模拟实验,采用合成照相法定量测定轧制过程中轧件的平面形状,探索了其变化规律,为中厚板平面形状控制建立数学模型提供了实用的方法。 相似文献
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根据某热轧厂R1轧机的轧制过程工艺参数,建立板坯在轧制过程中的三维动态非对称轧制的有限元模型,分析热轧板坯在轧制过程中头部翘曲的产生机理。通过仿真,分别探究轧辊辊径差、轧制线中心高度及板坯上下表面温差对轧件头部翘曲的单作用的影响规律,板坯头部翘曲的翘曲量随着非对称轧制条件程度的增加而增大。根据实际生产情况对R1轧机的轧制过程进行热力耦合仿真,综合考虑轧辊辊径差、轧制线中心高度和板坯上下表面温度差3个因素对板坯头部翘曲共同作用的影响,由仿真结果得到了有利于生产的"雪橇"式头部弯曲的轧制规程,从而对实际生产予以指导。 相似文献
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针对用三切分工艺生产带肋钢筋时,因预切分轧件头部左右弯曲引起轧制故障的问题,选用了新导卫装置。简要介绍了其装置结构及安装注意事项。使用新导卫取得了较理想的效果。 相似文献
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楔横轧工艺是一种先进的金属成形工艺,广泛应用于成形汽车变速箱的各种阶梯轴。在成形大尺寸非对称的阶梯轴时,轧制力不平衡会导致轧制过程中轧件在水平方向窜动,台阶尺寸不稳定且出现折叠,严重时无法成形;同时,轧件在切线方向摆动量大,从而造成产品弯曲。为了解决轧件台阶尺寸不稳定及弯曲,选取一种典型的非对称阶梯轴,在断面缩减率未超过75%时,采用两次轧制,选用较为合理的成形角和展宽角,同时对料头进行限制,利用有限元模拟软件Deform模拟分析成形过程,并进行试验。结果表明:采用两次轧制能够有效平衡轧制力,保证轧件尺寸稳定;90°直角形状料头比螺旋状料头更能有效限制轧件切向摆动,防止轧件弯曲。 相似文献
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介绍了龙形轧制方法,运用大变形热力耦合有限元法分析了龙形轧制和对称轧制铝合金厚板变形区内轧件的变形情况,比较了龙形轧制和对称轧制条件下轧板不同位置剪切应变的分布情况,并研究了上下轧辊错位量、异速比、摩擦系数和压下量对轧板心部剪切变形的影响。结果表明:对称轧制中厚板心部的剪切应变几乎为0;龙形轧制中由于有"搓轧区"存在,厚板心部的剪切应变远远大于对称轧制,且心部的剪切应变随着轧辊错位量、异速比、摩擦系数和压下量的增大而增大。为了获得较大的剪切应变同时保证较小的弯曲曲率,在龙形轧制中应合理选择这些工艺参数。 相似文献
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为实现轧机的高精度控制,提高产品加工质量,以轧机液压系统中伺服阀前蓄能器为研究对象,分析蓄能器动态特性对压下位置控制系统精度的影响。在实验轧机上,通过在伺服阀前更换不同公称容积蓄能器和改变蓄能器充气压力,定量分析其对液压压下位置控制系统的影响,最终确定该轧机伺服阀前蓄能器的最优参数,形成一套不局限于轧机液压系统的伺服阀前蓄能器的选型方法。 相似文献
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1 INTRODUCTIONLargealuminumslabsareusually producedinsuchelectromagneticcasting (EMC ) ,asshowninFig .1.TherollingfacesorbroadfacesoftheEMClargeslabstendtoform pull indefectduringcastingprocess,whichdirectlyinfluencesthequalityoftherollingfaces .Becauseofthisdefect,theexpenseofscalingtherollingfaceshastobeadded ,besides ,thehighqualitysurfacemetalhastobescaled ,thequali tyofslabsisdecreasedgreatly .Sotoobtainoriginalslabswithstraightrollingfaceswhichcanberolleddirectlyisasignificantta… 相似文献
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An analytical model for general asymmetrical cold rolling is proposed to investigate the behavior of sheet during asymmetrical
rolling using the slab analysis. Neutral points between the upper and lower rolls and the strip, rolling pressure distribution
along the contact interface of the roll and strip, and rolling forces, as well as rolling torque, can be calculated easily
using this model. Rolling pressure distribution, rolling force, and rolling torque, which are affected by various rolling
conditions such as roll speed ratio, thick-ness reduction, front and back tension, etc., are analyzed. Additionally, the limiting
rolling conditions be-tween reduction and roll speed ratio, or front and back tension, under which the rolling process can
be accomplished successfully, are discussed. By comparing analytical results and experimental measure-ments of rolling force,
it is apparent that the proposed model can successfully provide useful knowledge for designing the pass schedule of the asymmetrical
cold strip rolling process. 相似文献
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Ken-ichiro Mori Naohiro Oketani 《International Journal of Machine Tools and Manufacture》1999,39(3):146
A method using the finite element simulation for predicting coiling conditions of intermediate plates in a coilbox installed between roughing and finishing stands of hot strip rolling is proposed. In the coilbox, the intermediate plate is coiled to prevent the drop in temperature due to the radiation from the surface of the plate in the waiting period. In the present method, non-steady-state deformation of the plate in the coilbox is simulated by the finite element method, and the rolls are appropriately moved in accordance with the simulated results to form the plate in a coil. Since the formation of the coil is influenced by the bending shape near the front end of the plate, the deformation behaviour near the front end is monitored in the finite element simulation, and the positions of the rolls for coiling the plate are determined from instantaneous movement of the rolls once without trial and error. In addition, the coiling is stabilised by controlling the rotation of the roll. The predicted coiling conditions are applicable to actual coilbox machines. 相似文献
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