【作者】 郑永江；

【导师】 刘宏民； 申光宪；

【作者基本信息】 燕山大学 ， 机械设计及理论， 2013， 博士

【摘要】 四/六辊板带轧机共振及颤振现象在全世界范围内一直未得到有效解决，且轧机设计理论也未能给出轧机振动特性技术参数。历来轧机振动研究不区分轧机辊系是否稳定，均以稳定轧机建立力学模型，将轧辊垂直、水平、轴向、扭转、交叉及摇摆的空间振动行为作为各单一振动的耦合模式加以分析。为了抑制甚至消除轧机振动，本文从区分轧机辊系的稳定性和空间振动行为的思路出发研究轧机振动特性。首先，采用空间传递矩阵法作为轧机振动数值解析方法，并根据轧机多辊叠加的结构特点开发适合于轧机系统的多层多体系统空间传递矩阵法；同时以不同稳定性的两种二辊高刚度轧机为算例，利用上述方法对其进行空间振动解析并开展振动测试实验验证数值结果，最终建立空间传递矩阵法。其次，建立1580四辊热轧机的空间振动力学模型和有限元模型，同时考虑轧机部件间阻尼影响，运用上述空间传递矩阵法和有限元法对具有不同稳定性的两种轧机进行空间振动特性数值解析和仿真，并对比其固有振动特性，分析结果表明辊系间隙对轧机固有频率和振型的重要影响。进行轧机在线振动测试实验，一方面验证以上数值计算和仿真结果，另一方面从轧机的拍振及共振现象认知中提出1580mm四辊板带热轧机的自激振动机理，即在大压下率条件下，辊缝前、后滑区内轧件对轧辊做功不等进而引发负阻尼自激振动。从控制轧制工艺参数和改进轧机结构两方面提出抑制轧机振动的方法。最后，对650六辊冷轧机建立稳定性不同的两类轧机的空间振动模型，并利用空间传递矩阵法开展振动特性解析。开展650轧机的现场振动测试实验，验证数值结果的同时，探讨了引发薄带表面大斜浪板型的激励源并提出相应改进措施。综上所述，轧机空间振动及其数值解析法、辊缝前后滑区内的负阻尼自激振动机理及轧机抑振法的提出对轧机振动理论研究和实际轧制生产抑振具有重要的理论意义和工程应用价值。更多还原

【Abstract】 The resonant and chatter vibrations of4/6-h cold and hot rolling mills worldwidehave not been solved yet so far. Technical parameters about natural vibrationcharacteristics of rolling mills have not been given in design theory of the mill. Thestability of the roll system is not concerned in traditional research about mill vibrations,namely that the mechanical model of the mill is all built on stable rolling mill. Meanwhile,the spatial vibration behaviors involving vertical, horizontal, axial, torsional, cross andswinging vibration are analyzed as coupled vibration behaviors of single vibration. Tocontrol or even eliminate mill vibration, the new research about mill vibration is from thethought of stability of roll system and spatial behaviors of the mill.First, the spatial transfer matrix method is selected for vibration analysis of the mill.The multilayer and multi-body spatial transfer matrix method is built according to thestructural characteristics of more rolls. The two2-h rolling mills with different stability ofroll system are taken as examples and the spatial vibration analysis is conducted usingmentioned method. Meanwhile, the field test experiment is done as well to validatenumerical results. Finally, the spatial vibration transfer matrix method is built.Secondly, considering the effect of damping, the spatial vibration models of the1580hot plate4-h mill, including mechanical model and FEM model, are built. For two rollingmills with different stability of roll system, the numerical analysis and simulation aboutspatial vibration characteristics are conducted using transfer matrix method and finiteelement method. The comparison between vibration characteristics of two mills is doneand the effect of clearance on natural frequency and mode shape is demonstrated. Thefield test experiment is done to validate numerical calculation and simulation. Meanwhile,the self-excited vibration mechanism for the1580mill is proposed form the recognition ofbeat and resonant vibration phenomenon, i.e., self-excited vibration caused by negativedamping occurring in forward and backward slip zone of roll gap is generated due tounequal work that the strip exerts on the roll under heavy reduction rate. Vibration controlmethods are proposed from technical parameter controlling and modification of mill structure.Finally, the spatial vibration models of two650cold plate4-h mills with differentstability of roll system are built and the numerical analysis about spatial vibrationcharacteristics is conducted using transfer matrix method. The field test experiment isdone simultaneously to validate numerical results and discuss excitation source whichcauses big inclined wave on strip surface, and the corresponding modified vibrationcontrol methods are proposed.In conclusion, the spatial vibration and its numerical analytical method, self-excitedvibration mechanism caused by negative damping occurring in forward and backward slipzone, and presentation of vibration control method have a great theoretical andengineering application value for the theoretical research of mill vibration and practicalproduction vibration controlling.更多还原