Abstract:
The effective control of horizontal nonlinear vibration behavior of the mill work roll is a crucial scientific issue for ensuring equipment safety and stability. In this paper, we design an intelligent hydraulic lining plate installed between the mill portal frame and the upper work roll bearing seat. By reasonably controlling the unavoidable side clearance, the energy consumption caused by nonlinear vibrations is eliminated. The feasibility, correctness, and practicability of the intelligent lining plate design are demonstrated through a combination of theoretical analysis, numerical simulation, and experimental verification. This provides a new idea for nonlinear dynamics analysis and stability control of rolling mills, which has important guiding significance for practical production.
Keywords: horizontal nonlinear vibration; intelligent lining plate; vibration absorption; rolling mill; dynamic control
1. Introduction
The horizontal nonlinear vibration of the work roll in rolling mills significantly affects the stability and service life of the equipment. To address this issue, this paper proposes an intelligent lining plate design, aiming to reduce vibration amplitude and improve system stability.
2. Modeling of Horizontal Nonlinear Vibration of the Upper Work Roll in Rolling Mills
Considering factors such as horizontal dynamic excitation of the rolling force, nonlinear damping and stiffness between the work roll bearing seat and the portal frame, and clearances, a fractional-order dynamics model for horizontal nonlinear vibration of the mill work roll is established. The equation of horizontal nonlinear vibration of the upper work roll is derived, and its amplitude-frequency characteristic curve equation is obtained using the averaging method.
3. Influence Factors Analysis
The amplitude-frequency characteristic curve equation is analyzed to investigate the effects of various factors on system stability, including the amplitude of horizontal dynamic excitation of the rolling force, stiffness coefficients, nonlinear damping coefficients, and fractional-order differential terms.
Table 1: Factors Influencing System Stability
| Factor | Description |
|---|---|
| Amplitude of rolling force excitation (F) | Horizontal dynamic force applied to the work roll |
| Linear stiffness coefficient (k1) | Stiffness related to linear elastic deformation |
| Nonlinear stiffness coefficient (k2) | Stiffness related to nonlinear elastic deformation |
| Nonlinear damping coefficient (c) | Damping force proportional to the velocity of vibration |
| Fractional-order differential term (p) | Order of fractional derivative in the vibration equation |
4. Design of Intelligent Lining Plate
To effectively control horizontal nonlinear vibration, an intelligent hydraulic lining plate is designed. It is installed between the mill portal frame and the upper work roll bearing seat, aiming to absorb and dissipate vibration energy by controlling the unavoidable side clearance.
4.1 Composition and Working Principle
The intelligent lining plate consists of a base plate made of wear-resistant steel NM360 and a lining plate made of spring steel 60Si2Mn. An elliptical working chamber is formed between the base plate and the lining plate, sealed with an O-ring to prevent hydraulic oil leakage.
When the pressure of hydraulic oil in the working chamber exceeds a set threshold, the intelligent lining plate adjusts the pressure in real-time through a pressure closed-loop system consisting of a pressure sensor and a servo valve, thereby dynamically regulating horizontal damping and stiffness.
4.2 Dynamic Characteristics Analysis
The equivalent damping (c0) and equivalent stiffness (k0) of the intelligent lining plate are defined. The horizontal nonlinear vibration equation of the upper work roll with the intelligent lining plate is derived based on the energy conservation law.
5. Numerical Simulation and Experimental Verification
5.1 Numerical Simulation
Numerical simulations are conducted to analyze the influence of intelligent lining plate parameters (c0 and k0) on the amplitude-frequency characteristic curve of the roll system. The results show that installing the intelligent lining plate significantly reduces the vibration amplitude and resonance region of the roll system.
5.2 Experimental Verification
To validate the feasibility of the intelligent lining plate, a 150 mm two-high rolling mill vibration absorption test rig is built based on modern testing technology. Acceleration sensors, a multi-channel data acquisition instrument, and data processing and vibration signal analysis software are used.
Table 2: Experimental Setup and Results
| Rolling Speed (r/min) | Working Pressure of Lining Plate (MPa) | Vibration Energy Reduction (%) |
|---|---|---|
| 90 | 3 | 16.5 |
| 5 | 21.4 | |
| 7 | 26.2 | |
| 120 | 3 | 19.0 |
| 5 | 22.1 | |
| 7 | 26.1 | |
| 150 | 3 | 21.5 |
| 5 | 25.6 | |
| 7 | 28.9 |
The experimental results show that as the working pressure of the lining plate increases, the vibration waveform amplitude gradually decreases, and the vibration energy gradually weakens. Compared to the system without a lining plate, the vibration energy of the roll system decreases by about 19% when the working pressure of the lining plate is 3 MPa, 22.1% when it is 5 MPa, and 26.1% when it is 7 MPa.
6. Conclusion
In this paper, a fractional-order dynamics model for horizontal nonlinear vibration of the mill work roll is established, considering factors such as rolling force horizontal dynamic excitation, nonlinear damping, nonlinear stiffness, and clearances. An intelligent hydraulic lining plate is designed to control horizontal nonlinear vibration by reasonably controlling the unavoidable side clearance. Through numerical simulation and experimental verification, it is proven that the intelligent lining plate can effectively reduce the vibration amplitude and resonance region of the roll system, improving its stability.
This research provides a new idea for nonlinear dynamics analysis and stability control of rolling mills, which has important practical significance for ensuring the safe and stable operation of rolling equipment. Future work will focus on optimizing the design of the intelligent lining plate and exploring its application in different types of rolling mills.