Analysis of Regenerative Chatter in Tandem Cold Rolling Mills

Abstract

Regenerative chatter in tandem cold rolling mills poses a significant challenge to process stability and productivity, arising from complex interactions between process dynamics and structural vibrations. In this paper a novel stability criterion for regenerative chatter based on linear analysis tools is introduced, offering a more precise and computationally efficient alternative to other methods present in the literature to compute the critical speed starting from a linear chatter model. The criterion serves as the foundation for generating multi-parametric stability charts that provide valuable insights into the underlying phenomena and help clarify discrepancies reported in previous studies. Furthermore, an innovative parameterization is introduced to investigate the effects on regenerative chatter of structural modifications on the stands, revealing that aligning the resonance of the downstream stand with the anti-resonance of the upstream stand substantially enhances system stability. The proposed tool enables the evaluation of stability over a fine parameter grid within minutes, while previous approaches yield results after multiple computational hours.