Chatter in the Strip Rolling Process, Part 3: Chatter Model

1998 ◽  
Vol 120 (2) ◽  
pp. 343-348 ◽  
Author(s):  
I-S. Yun ◽  
K. F. Ehmann ◽  
W. R. D. Wilson
Keyword(s):  
Mode Coupling ◽  
Metal Cutting ◽  
Dynamic Instability ◽  
Rolling Process ◽  
Central Problem ◽  
Strip Rolling ◽  
Basic Understanding ◽  
Negative Damping

The central problem of the analysis and prevention of chatter in rolling operations is in understanding the conditions which lead to dynamic instability. By analogy with metal cutting operations, it appears that a few basic mechanisms may be responsible for the occurrence of self-excited vibrations in rolling. The three most significant mechanisms are: negative damping, mode-coupling and regeneration. In this paper, negative damping and mode-coupling are considered separately in an “artificial” manner to make inroads toward a better basic understanding of rolling instability.

Regenerative Chatter in High-Speed Tandem Rolling Mills

2006 ◽  
Author(s):  
Huyue Zhao ◽  
Kornel F. Ehmann
Keyword(s):  
Mode Coupling ◽  
High Speed ◽  
Process Model ◽  
Structural Model ◽  
Rolling Process ◽  
Space Representation ◽  
Regenerative Chatter ◽  
State Space Representation ◽  
Negative Damping ◽  
Delay Differential

Third-octave-mode chatter, the most detrimental form of rolling chatter, is generated by means of negative damping, mode coupling, and regeneration. While mechanisms that include negative damping, and mode coupling have been thoroughly investigated, those associated with the regenerative effect remain elusive. In this paper, the mechanisms that may lead to regenerative chatter are studied through a state-space representation of a multi-stand mill that is constructed by coupling a homogenous dynamic rolling process model with a structural model for the mill stands in a high-speed tandem mill configuration. Stability analysis, by using the integral criterion for the stability of systems described by delay differential equations, is carried out for the regenerative mechanism in order to better understand the effects of rolling parameters on a single stand as well as the overall system. Preliminary simulation results, based on the proposed chatter model, are presented to demonstrate the feasibility and the accuracy of the chatter model, as well as to investigate chatter phenomena too complex to be studied analytically.

Optimization of Rolling Modes on the Mill 1700 of JSC "ArselorMittal Temirtau" with Aim to Increase Quality of Sheet Rolled Products

2015 ◽  
Vol 1095 ◽  
pp. 786-794
Author(s):  
A.B. Naizabekov ◽  
V.A. Talmazan ◽  
S.N. Lezhnev ◽  
E.A Panin ◽  
А.S. Erzhanov ◽  
...  
Keyword(s):  
Surface Defects ◽  
Mechanical Damage ◽  
Rolling Process ◽  
Rolled Sheet ◽  
Strip Rolling ◽  
Technological Factors ◽  
Second Stage ◽  
Sheet Surface ◽  
Cold Rolled

Used the influence of technological factors of the rolling process on the intensity of the rolling out of the defect to determine the value of deformation and the coefficient of use of the plasticity resource. Introduced the notion of residual coefficient of plasticity resource in the second stage of transformation of the defect. Found that the causes of deterioration of the quality of cold-rolled sheet can be numerous defects of mechanical origin, caused by mechanical damage of the sheet surface. Conducted an analysis of profiles rolling modes, rolled on the mill 1700. With the use of existing methods calculated DUPR on workshop modes of rolling of specified profiles with and without considering the surface defects. Carried an optimization of the modes of strip rolling with surface defects.

Does a Predictive Minimal Model of Friction-Induced Vibration Exist?

2010 ◽  
Author(s):  
Tore Butlin ◽  
Jim Woodhouse
Keyword(s):  
Minimal Model ◽  
Mode Coupling ◽  
Test System ◽  
Minimal Models ◽  
Pin On Disc ◽  
Limited Frequency ◽  
Extensive Program ◽  
Negative Damping ◽  
Model Of Friction ◽  
Friction Induced Vibration

Highly idealised models of friction-induced vibration have been motivated by an attempt to capture what is essential to the phenomenon. This approach has resulted in a few simple mechanisms that are thought to capture common routes to instability. This paper aims to determine how well these perform as approximations to a more complex system, and whether the essential ingredients needed for a minimal model can be identified. We take a reduced-order model that exemplifies ‘mode-coupling’ and explore the extent to which it can approximate predictions based on an experimentally identified test-system. For the particular test system under study, two-mode ‘mode-coupling’ is rarely a good approximation and three modes are usually required to model a limited frequency range. We then compare predictions with results from an extensive program of sliding contact tests on a pin-on-disc rig in order to identify which ingredients are needed to explain observed squeal events. The results suggest that several minimal models would be needed to describe all observed squeal initiations, but the ‘negative-damping’ route to instability, which requires a velocity-dependent friction law, convincingly accounts for one cluster.

The Study of Deformability of Heat-Resistant Alloy Named “Inconel Alloy 625” for Estimation of Plates Production Possibility at Wide-Strip Rolling “Mill 2300”

2019 ◽  
Vol 946 ◽  
pp. 818-822 ◽  
Author(s):  
Nikita S. Deryabin
Keyword(s):  
Mathematical Model ◽  
Rolling Mill ◽  
Cooling System ◽  
Rolling Process ◽  
Inconel 625 ◽  
Technological Parameters ◽  
Strip Rolling ◽  
Cracking Behavior ◽  
Inconel Alloy ◽  
Alloy 625

The hot deformation behavior of the Inconel alloy 625 was investigated through compression test within the temperature range of 850–1250 °C and the strain rate range of 0.1–30 s−1. Physically based mathematical model involving dynamic recovery and dynamic recrystallization processes has been proposed. Mathematical model allowed to calculate technological parameters of a rolling process of the “Inconel 625” at the hot rolling mill 2300. The pilot rolling operations showed that the possibility of the “Inconel 625” production exists. But it is necessary to provide the design changes of the cooling system of the work rolls. The article addressed the cracking behavior of nickel alloys in industries such as chemical process, nuclear generation, aircraft engine production.

scholarly journals System Identification for Gage Control Property of Strip Rolling Process

2004 ◽  
Vol 90 (11) ◽  
pp. 941-946 ◽  
Author(s):  
Yoshiro WASHIKITA ◽  
Yasunori KADOYA ◽  
Kazuyoshi KIMURA
Keyword(s):  
System Identification ◽  
Rolling Process ◽  
Strip Rolling

An Efficient Way of Calculating Temperatures in the Strip Rolling Process

1998 ◽  
Vol 120 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Der-Form Chang
Keyword(s):  
Heat Transfer ◽  
Rolling Direction ◽  
Rolling Process ◽  
Strip Rolling ◽  
One Dimensional ◽  
Lubrication Regimes ◽  
Real Area Of Contact ◽  
Lagrangian Coordinate ◽  
Efficient Heat Transfer ◽  
Real Area

The two-dimensional heat transfer between the strip and rolls in strip rolling is modeled by one-dimensional heat conduction equations adopting Lagrangian coordinate systems on the contact surfaces. Finite difference formulations are used in the rolling direction and analytical solutions are applied normal to this direction, making computation more efficient. Heat transfer in the sticking region is considered. The influence of real area of contact on heat transfer is also taken into account, resulting in a method capable of modeling the strip rolling process operated in any of several different lubrication regimes. This method provides good temperature predictions.

Mathematical modelling of roll wear in a tandem mill hot strip rolling process

2013 ◽  
Vol 4 (1) ◽  
pp. 56
Author(s):  
Carlos Arturo Vega Lebrún ◽  
Rumualdo Servin Castañeda ◽  
Genoveva Rosano Ortega ◽  
Juan Manuel Lopez ◽  
José Luis Cendejas Valdéz ◽  
...  
Keyword(s):  
Mathematical Modelling ◽  
Rolling Process ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Hot Strip ◽  
Roll Wear
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