Third-octave-mode chatter in rolling. Part 1: Chatter model

Abstract

Among various types of rolling chatter, third-octave-mode chatter is considered the most critical because it generates large gauge variations in the rolled materials and may damage the rolling mill. In this three-part paper, a new chatter model that combines a homogeneous process model with suitable mill structure models is presented. Based on this model, the system's stability is investigated in the light of various mechanisms that may lead to the onset of third-octave-mode chatter. Stability criteria for each mechanism are established in terms of relevant rolling process parameters, and their influences on overall system stability are demonstrated. Part 1 deals with the general formulation of single- and multiple-stand chatter models.

Research on Critical Rolling Speed of Self-excited Vibration in the Tandem Rolling Process of Thin Strip

“…着数值计算能力和理论研究方法的发展，轧机振动 问题进入新的研究阶段，国内外专家学者针对多模 态耦合振动 [9][10][11] 、非线性因素 [12][13][14][15][16] 、塑形变形过 程 [17][18] 、界面摩擦与润滑 [19][20] 、连续轧制 [21] 等结构 与工艺问题的考虑，从理论分析、数值计算、试验 模拟及工程验证等多方面进行了研究，郜志英等 [22] 对近十几年的发展现状进行了详细的综述。 …”

Theoretical and Experimental Analysis of Chatter in Tandem Cold Rolling Mills Based on Wave Propagation Theory

“…The difference in these velocities causes a variable tension to the strip. Variation of the tension (dσ) is determined in the simple theory by Arimura et al 23) and was used by Tamiya et al 18) and later on by other researchers [19][20][21] where V1 is the input strip velocity of the current stand, Vex is the exit velocity from the previous one, E is the elastic modulus, L is the inter-stand distance and t is the time. Variation in tensions causes the rolling force variation.…”

“…6,21,[29][30][31] The dynamics of the mill structure and that of the rolling process will be separately modeled, and chatter model will be constructed based on the interaction between these two models.…”

“…The chatter model for a single stand can be formulated by combining the rolling process model with the structural model and by considering the interactions between neighboring stands 20,21,29,30) as schematically shown in Fig. 6(a).…”

“…This model presents a dynamic relationship between rolling parameters, and relaxes some assumptions in the previous models. It is pointed out by Hu et al 21) that there are four significant mechanisms for third octave chatter: model matching, negative damping, mode coupling, and regenerative.…”