The shape and thickness qualities of strip are influenced by the vibration of rolling mill. At present, the researches on the vibration of rolling mill are mainly the vertical vibration and torsional vibration of sing...The shape and thickness qualities of strip are influenced by the vibration of rolling mill. At present, the researches on the vibration of rolling mill are mainly the vertical vibration and torsional vibration of single stand mill, the study on the vibration of tandem rolling mill is rare. For the vibration of tandem rolling mill, the key problem is the vibration of the moving strip between stands. In this paper, considering the dynamic of moving strip and rolling theory, the vertical vibration of moving strip in the rolling process was proposed. Take the moving strip between the two mills of tandem rolling mill in the rolling process as subject investigated, according to the theory of moving beam, the vertical vibration model of moving strip in the rolling process was established. The partial differential equation was discretized by Galerkin truncation method. The natural frequency and stability of the moving strip were investigated and the numerical simulation in time domain was made. Simulation results show that, the natural frequency was strongly influenced by the rolling velocity and tension. With increasing of the rolling velocity, the first three natural frequencies decrease, the fourth natural frequency increases; with increasing of the unit tension, when the rolling velocity is high and low, respectively, the low order dimensionless natural frequency gradually decreases and increases, respectively. According to the stability of moving strip, the critical speed was determined, and the matching relationship of the tension and rolling velocity was also determined. This model can be used to study the stability of moving strip, improve the quality of strip and develop new rolling technology from the aspect of dynamics.展开更多
Taking the moving strip between two stands of some tandem rolling mill in rolling process as a subject for investigation, according to the Poisson-Kirchhoff sheet theory, the vibration model of the moving strip in rol...Taking the moving strip between two stands of some tandem rolling mill in rolling process as a subject for investigation, according to the Poisson-Kirchhoff sheet theory, the vibration model of the moving strip in rolling process was established. Model of distributed stress was built based on rolling theory. And then, vibration model of moving strip with distributed stress was established. The partial differential equation was discretized by Galerkin truncation. The natural frequency and stability of the moving strip were investigated and simulation in time domain was made by numerical method. Taking the moving strip between the second stand and third stand of some tandem mill as a subject for investigation, distributions of stress, natural frequencies and stability of moving strip were de- termined under six different rolling conditions which are ＂uniform distribution of stress＂, ＂flat roll flat＂, ＂flat roll convex＂, ＂flat roll concave＂, ＂convex roll flat＂ and ＂concave roll flat＂. At last, three-dimensional dynamic simulation was made and the moving law of the strip was determined. This model can be used to study the stability of moving strip, depress the shape wave of strip and develop new rolling technology from the aspect of dynamics.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 50875231)Hebei Provincial Major Natural Science Foundation of China (Grant No. E2006001038)
文摘The shape and thickness qualities of strip are influenced by the vibration of rolling mill. At present, the researches on the vibration of rolling mill are mainly the vertical vibration and torsional vibration of single stand mill, the study on the vibration of tandem rolling mill is rare. For the vibration of tandem rolling mill, the key problem is the vibration of the moving strip between stands. In this paper, considering the dynamic of moving strip and rolling theory, the vertical vibration of moving strip in the rolling process was proposed. Take the moving strip between the two mills of tandem rolling mill in the rolling process as subject investigated, according to the theory of moving beam, the vertical vibration model of moving strip in the rolling process was established. The partial differential equation was discretized by Galerkin truncation method. The natural frequency and stability of the moving strip were investigated and the numerical simulation in time domain was made. Simulation results show that, the natural frequency was strongly influenced by the rolling velocity and tension. With increasing of the rolling velocity, the first three natural frequencies decrease, the fourth natural frequency increases; with increasing of the unit tension, when the rolling velocity is high and low, respectively, the low order dimensionless natural frequency gradually decreases and increases, respectively. According to the stability of moving strip, the critical speed was determined, and the matching relationship of the tension and rolling velocity was also determined. This model can be used to study the stability of moving strip, improve the quality of strip and develop new rolling technology from the aspect of dynamics.
基金Item Sponsored by National Natural Science Foundation of China(50875231)Great Natural Science Foundation of Hebei Province of China(E2006001038)
文摘Taking the moving strip between two stands of some tandem rolling mill in rolling process as a subject for investigation, according to the Poisson-Kirchhoff sheet theory, the vibration model of the moving strip in rolling process was established. Model of distributed stress was built based on rolling theory. And then, vibration model of moving strip with distributed stress was established. The partial differential equation was discretized by Galerkin truncation. The natural frequency and stability of the moving strip were investigated and simulation in time domain was made by numerical method. Taking the moving strip between the second stand and third stand of some tandem mill as a subject for investigation, distributions of stress, natural frequencies and stability of moving strip were de- termined under six different rolling conditions which are ＂uniform distribution of stress＂, ＂flat roll flat＂, ＂flat roll convex＂, ＂flat roll concave＂, ＂convex roll flat＂ and ＂concave roll flat＂. At last, three-dimensional dynamic simulation was made and the moving law of the strip was determined. This model can be used to study the stability of moving strip, depress the shape wave of strip and develop new rolling technology from the aspect of dynamics.
