基于辊系刚柔耦合特性的板带轧机系统动力学建模研究

发布时间：2018-01-17 20:04

本文关键词：基于辊系刚柔耦合特性的板带轧机系统动力学建模研究　出处：《燕山大学》2016年博士论文　论文类型：学位论文

【摘要】：金属板带在国民经济和国防现代化建设中起着非常重要的作用。轧制过程是一个典型的复杂非线性动态过程,其动力学特性是由轧机辊系和运动板带的不同物理属性的运动通过相互耦合作用而决定的。本文以四辊热连轧机组为研究对象,通过分析轧制过程中辊系、板带的运动特征及其耦合关系,揭示基于辊系刚柔耦合特性的板带轧机系统动力学机理,建立相应动力学模型,并在此基础上进行仿真分析。综合考虑辊系的垂直运动、水平运动、轧辊的转动以及板带刚性运动和弹性变形,通过动力学分析,实现柔性多体机械系统中刚体和可变形体位移场的描述,进而确定由于系统构件刚性运动与弹性变形同时作用引起的强非线性惯性耦合与刚度耦合作用规律,建立板带轧机辊系刚性振动耦合动力学机理模型,分析耦合作用下辊系的动态响应和轧机工作稳定性,为实现轧件厚度动态控制提供理论依据。充分考虑轧制过程中轧机系统刚性振动对轧辊弯曲变形动特性的影响。通过运动学分析,实现柔性多体机械系统中刚体和可变形体的位移场描述,建立板带轧机辊系刚柔耦合动力学模型。对轧机辊系进行耦合运动模态分析,进一步探讨轧辊变形运动振动频率和模态振型函数的解析解,并比较不同时刻下,由传统结构动力学求得的轧辊固有模态振型函数与考虑轧机系统刚性振动时的轧辊模态振型函数的区别。考虑轧制过程中轧辊运动与轧制变形区动特性的耦合作用规律,通过运动学分析,实现辊系-轧件动力学系统的位移场描述,建立板带轧机辊系-轧件多参数耦合动力学模型。对轧机辊系进行耦合运动模态分析,进一步探讨轧辊变形模态振型函数的解析解,并分析变形区内金属横向流动位移的运动特征。建立基于辊系刚柔耦合特性的板带轧机系统动力学仿真模型,包括以下几方面:轧机辊系刚性振动耦合动力学模型、轧机辊系刚柔耦合动力学模型、轧制变形区耦合动力学模型。同时考虑工作辊沿垂直和水平方向的运动特征,对变形区轧制力学模型进行了修正。由于轧辊横向模态函数随辊系刚性运动而时刻变化,基于模型本身特点,选取了中心差分法对系统进行仿真计算。从而得到基于辊系刚柔耦合特性的板带轧机系统动力学模型,并进行了仿真分析。该模型可对轧制过程进行模拟,能反映板形板厚综合动态信息,为虚拟轧制提供理论基础,并为先进控制理论应用提供平台。本文从物理、力学特性的角度出发,结合轧件-辊系耦合非均匀变形,真实的反映出轧机辊系和金属板带动态特性,揭示了轧制过程中轧制稳定性、带钢表面振纹、咬钢抛钢等动态过程的产生机理。耦合动力学机理模型对推动轧机系统动态建模的发展,提高轧制过程控制精度具有重要理论和实用价值。
[Abstract]:Metal strip plays a very important role in national economy and national defense modernization. Rolling process is a typical complex nonlinear dynamic process. Its dynamic characteristics are determined by the interaction between the motion of different physical properties of the rolling mill roll system and the moving plate strip. This paper takes the four-high hot strip mill as the research object and analyzes the roll system during the rolling process. The motion characteristics of plate and strip and its coupling relationship reveal the dynamic mechanism of strip rolling mill system based on roll system rigid-flexible coupling characteristics and establish the corresponding dynamic model. On the basis of the simulation analysis, the vertical motion, horizontal movement, roll rotation, rigid motion and elastic deformation of the strip were considered synthetically, and the dynamic analysis was carried out. The displacement field of rigid body and variable body in flexible multi-body mechanical system is described, and the law of strong nonlinear inertial coupling and stiffness coupling caused by the simultaneous action of rigid motion and elastic deformation of the system member is determined. The dynamic mechanism model of rigid vibration coupling of roll system of strip mill is established, and the dynamic response of roll system and the working stability of rolling mill under coupling action are analyzed. This paper provides a theoretical basis for dynamic control of roll thickness and fully considers the influence of the rigid vibration of rolling mill system on the dynamic characteristics of roll bending deformation. The kinematics analysis is carried out. The displacement field of rigid body and variable body in flexible multi-body mechanical system is described, and the rigid-flexible coupling dynamic model of roll system of plate and strip mill is established, and the coupling motion modal analysis of roll system of rolling mill is carried out. The analytical solutions of vibration frequency and modal mode function of roll deformation motion are discussed and compared at different times. The difference between the inherent modal mode function of roller obtained from the traditional structural dynamics and the modal mode function of roll considering the rigid vibration of rolling mill system. The coupling of roll motion and dynamic characteristics of rolling deformation zone during rolling process is considered. Use the pattern. Through kinematics analysis, the displacement field description of roll system and rolling piece dynamics system is realized, and the multi-parameter coupling dynamic model of strip mill roll system is established, and the coupling motion mode analysis of rolling mill roll system is carried out. The dynamic simulation model of strip rolling mill system based on the coupling characteristics of rigid and flexible roll system is established by analyzing the analytical solution of the modal mode mode function of roll deformation and the kinematic characteristics of metal transverse flow in the deformation zone. It includes the following aspects: the dynamic model of rigid vibration coupling of rolling mill roll system, the rigid-flexible coupling dynamic model of rolling mill roll system. The coupled dynamic model of rolling deformation zone is developed, and the motion characteristics of the work roll along the vertical and horizontal directions are taken into account at the same time. The rolling mechanics model in the deformation zone is modified. Because the lateral mode function of roll changes with the rigid movement of the roll system, it is based on the characteristics of the model itself. The central differential method is selected to simulate the system, and then the dynamic model of strip mill system based on the coupling characteristics of rigid and flexible roll system is obtained, and the simulation analysis is carried out. The model can be used to simulate the rolling process. It can reflect the comprehensive dynamic information of plate thickness, provide the theoretical basis for virtual rolling, and provide a platform for the application of advanced control theory. This paper starts from the point of view of physical and mechanical properties. Combined with the coupling non-uniform deformation of workpiece and roll system, the dynamic characteristics of roll system and metal strip are truly reflected, and the rolling stability and strip surface vibration are revealed during the rolling process. The coupling dynamic mechanism model has important theoretical and practical value in promoting the development of dynamic modeling of rolling mill system and improving the control precision of rolling process.
【学位授予单位】：燕山大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG333.7

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