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Coupled Dynamic Modeling of Rolls Model and Metal Model for Four High Mill Based on Strip Crown Control

Chinese Journal of Mechanical Engineering 2013年第1期26卷 144-150页

作者： SUN Jianliang PENG Yan liu hongmin National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University State Key Laboratory of Metastable Materials Science & Technology Yanshan University

The crown is a key quality index of strip and plate, the rolling mill system is a complex nonlinear system, the strip qualities are directly affected by the dynamic characteristics of the rolling mil. At present, the studies about the dynamic modeling of the rolling mill system mainly focus on the dynamic simulation for the strip thickness control system, the dynamic characteristics of the strip along the width direction and that of the rolls along axial direction are not considered. In order to study the dynamic changes of strip crown in the roiling process, the dynamic simulation model based on strip crown control is established. The work roll and backup roll are considered as elastic continuous bodies and the work roll and backup roll are joined by a Winkler elastic layer. The rolls are considered as double freely supported beams. The change rate of roll gap is taken into consideration in the metal deformation, based on the principle of dynamic conservation of material flow, the two dimensional dynamic model of metal is established. The model of metal deformation provides exciting force for the rolls dynamic model, and the roils dynamic model and metal deformation model couple together. Then, based on the two models, the dynamic model of rolling mill system based on strip crown control is established. The Newmark-13 method is used to solve the problem, and the dynamic changes of these parameters are obtained as follows：（1） The bending of work roll and backup roll changes with time; （2） The strip crown changes with time; （3） The distribution of rolling force changes with time. Take some cold tandem rolling mill as subject investigated, simulation results and the comparisons with experimental results show that the dynamic model built is rational and correct. The proposed research provides effective theory for optimization of device and technological parameters and development of new technology, plays an important role to improve the strip control precision and str

关键词： strip crown transverse vibration of rolls dynamic simulation dynamic conservation of material flow

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Establishment Method of Shape Standard Curve Based on Stepwise Optimization and Its Compensation Models

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Chinese Journal of Mechanical Engineering 2011年第1期24卷 105-112页

作者： SUN Yabo liu hongmin PENG Yan Engineering Research Center of Rolling Equipment and Complete Technology of Ministry of Education Yanshan University Qinhuangdao 066004 China State Key Laboratory of Metastable Materials Science ＆ Technology Yanshan University Qinhuangdao 066004 China

There are very few researches on the shape standard curve currently,and they merely remain on the level of description of the general concept and production experiences,lacking of the in-depth theoretical analysis,and the concrete principle,method and steps for determining the shape standard curve are not put forward,therefore,they are not applicable in industrial *** is the weakest spot in the research on the basic shape *** this paper,the basic shape standard curve and the transverse distribution curve of the exit thickness are attained with stepwise optimization,which is based on the theoretical calculation method of the shape standard curve of strip mills proposed by *** calculating the shape discrimination model and the shape forecast model separately,the simultaneous iterative calculation by the previous method is avoided,and the speed and stability of calculation are *** compensation models of the transverse temperature difference of the strip,the shape detection roller deflection and the shape of the strip coil are established,respectively,meantime,the basic shape standard curves are compensated,and the relatively perfect theoretical establishment method of the shape standard curve is *** simulation and calculation are done on a 1 220 mm five-stand cold strip tandem *** simulation and calculation result shows that the principle,method and steps for determining the shape standard curve are correct and feasible,and the correctness of theoretical analysis and calculation is *** paper proposes an idea and a method for the establishment of the shape standard curve in the rolling processes of cold strip mills,which develop the theory and model of the shape standard curve and improve the quality and efficiency of the shape control in the rolling processes of cold strip mills.

关键词： strip rolling shape crown shape standard curve stepwise optimization compensation model

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Analysis of Wear Mechanism and Influence Factors of Drum Segment of Hot Rolling Coiler

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Chinese Journal of Mechanical Engineering 2013年第2期26卷 351-355页

作者： ZHANG Jian PENG Yan liu hongmin liu Yunfei National Engieering Research Center for Equipment and Technology of Cold Rolling Strip Yanshan University State Key Laboratory of Metastable Materials Science and Technology Yanshan University

Because the work environment of segment is complex, and the wear failures usually happen, the wear mechanism corresponding to the load is a key factor for the solution of this problem. At present, many researchers have investigated the failure of segment, but have not taken into account the compositive influences of matching and coiling process. To investigate the wear failure of the drum segment of the hot rolling coiler, the MMU-5G abrasion tester is applied to simulate the wear behavior under different temperatures, different loads and different stages, and the friction coefficients and wear rates are acquired. Scanning electron microscopy（SEM） is used to observe the micro-morphology of worn surface, X-ray energy dispersive spectroscopy（EDS） is used to analyze the chemical composition of worn surface, finally the wear mechanism of segment in working process is judged and the influence regulars of the environmental factors on the material wear behaviors are found. The test and analysis results show that under certain load, the wear of the segment changes into oxidation wear from abrasive wear step by step with the temperature increases, and the wear degree reduces; under certain temperature, the main wear mechanism of segment changes into spalling wear from abrasive wear with the load increases, and the wear degree slightly increases. The proposed research provides a theoretical foundation and a practical reference for optimizing the wear behavior and extending the working life of segment.

关键词： friction coefficient wear rate micro-morphology wear mechanism wear resistance

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Strip Layer Method for Analysis of the Three-Dimensional Stresses and Spread of Large Cylindrical Shell Rolling

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Chinese Journal of Mechanical Engineering 2015年第3期28卷 556-564页

作者： liu hongmin CHEN Suwen PENG Yan SUN Jianliang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University State Key Laboratory of Metastable Materials Science & Technology Yanshan University

As the traditional forging process has many problems such as low efficiency, high consumption of material and energy, large cylindrical shell rolling is introduced. Large cylindrical shell rolling is a typical rotary forming technology, and the upper and lower rolls have different radii and speeds. To quickly predict the three-dimensional stresses and eliminate fishtail defect, an improved strip layer method is developed, in which the asymmetry of the upper and lower rolls, non-uniform deformation and stress, as well as the asymmetrical spread on the end surface are considered. The deformation zone is divided into a certain number of layers and strips along the thickness and width, respectively. The transverse displacement model is constructed by polynomial function, in order to increase the computation speed greatly. From the metal plastic mechanics principle, the three-dimensional stress models are established. The genetic algorithm is used for optimization calculation in an industrial experiment example. The results show that the rolling pressure, the normal stresses, the upper and lower friction stress distributions are not similar with those of a general plate rolling. There are two relative maximum values in rolling pressure distribution. The upper and lower longitudinal friction stresses change direction nearby the upper and lower neutral points, respectively. The fishtail profile of spread on the end surface is predicted satisfactorily. The reduction could be helpful to eliminate fishtail defect. The large cylindrical shell rolling example illustrates the calculation results acquired rapidly are good agreements with the finite element simulation and experimental values of previous study. A highly effective and reliable three-dimensional simulation method is proposed for large cylindrical shell rolling and other asymmetrical rolling.

关键词： large cylindrical shell rolling strip layer method three-dimensional stresses rolling pressure friction stress spread

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Flatness Control Based on Dynamic Effective Matrix for Cold Strip Mills

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Chinese Journal of Mechanical Engineering 2009年第2期22卷 287-296页

作者： liu hongmin HE Haitao SHAN Xiuying JIANG Guangbiao Engineering Research Center of Rolling Equipment and Complete Technology of Ministry of Education Yanshan University Qinhuangdao 066004 China State Key Laboratory of Metastable Materials Science ＆ Technology Yanshan University Qinhuangdao 066004 China College of Information Science and Engineering Yanshan University Qinhuangdao 066004 China Baogang Branch Baoshan Iron and Steel Co. Ltd. Shanghai 200941 China

Steel strips are the main of steel products and flatness is an important quality indicator of steel strips. Flatness control is the key and highly difficult technique of strip mills. The bottle-neck restricting the improvement of flatness control techniques is that the research on flatness theories and control mathematic models is not in accordance with the requirement of technique developments. To build a simple, rapid and accurate explicit formulation control model has become an urgent need for the development of flatness control technique. This paper puts forward the conception of dynamic effective matrix based on the effective matrix method for flatness control proposed by the authors under the consideration of the influence of the change of parameters in roiling processes on the effective matrix, and the concept is validated by industrial productions. Three methods of the effective matrix generation are induced： the calculation method based on the flatness prediction model; the calculation method based on the data excavation in rolling processes and the direct calculation method based on the network model. A fuzzy neural network effective matrix model is built based on the clusters, and then the network structure is optimized and the high-speed-calculation problem of the dynamic effective matrix is solved. The flatness control scheme for cold strip mills is proposed based on the dynamic effective matrix. On stand 5 of the 1 220 mm five-stand 4-high cold strip tandem mill, the industrial experiment with the control methods of tilting roll and bending roll is done by the control scheme of the static effective matrix and the dynamic effective matrix, respectively. The experiment result proves that the control effect of the dynamic effective matrix is much better than that of the static effective matrix. This paper proposes a new idea and method for the dynamic flatness control in the rolling processes of cold strip mills and develops the theory and model of the fl

关键词： cold strip mill flatness control dynamic effective matrix cluster fuzzy neural network

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Vertical Vibration of Moving Strip in Rolling Process Based on Beam Theory

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Chinese Journal of Mechanical Engineering 2009年第5期22卷 680-687页

作者： SUN Jianliang PENG Yan liu hongmin JIANG Guangbiao Engineering Research Center of Rolling Equipment and Complete Technology of Ministry of Education Yanshan University Qinhuangdao 066004 China State Key Laboratory of Metastable Materials Science ＆ Technology Yanshan University Qinhuangdao 066004 China Hot Rolling Mill of Baoshan Iron and Steel Company Shanghai 200941 China

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.

关键词： moving strip vertical vibration galerkin truncation method stability

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Determination of Optimal Work Roll Profile for Cold Strip Mill

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Journal of Iron and Steel Research International 1998年第1期5卷 8-12页

作者： Wang Hongxu Lian Jiachuang liu hongmin Yanshan University

The model of predicting distribution of strip thickness at the exit and tension stress is established by using weighted residual method and variational method with consideration of rolled metal lateral flow.A New method of calculating loaded roll gap in relation to target tension stress is *** minimum square summation of loaded roll gap deviation is used as an objective function for the first time to optimize initial work roll profile.

关键词： work roll profile cold rolling optimization weighted residual method variational method strip

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Unsupervised Multi-Expert Learning Model for Underwater Image Enhancement

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 708-722页

作者： hongmin liu Qi Zhang Yufan Hu Hui Zeng Bin Fan the School of Intelligence Science and Technology and the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China the School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China IEEE

Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded *** methods feed the whole image directly into the model for ***,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the *** address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color ***,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater *** on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater ***,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,*** addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced *** experiments on public datasets demonstrate that our method achieves more pleasing results in vision *** metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.

关键词： Multi-expert learning underwater image enhancement unsupervised learning

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Synthesis of Indole Derivatives from 2-Keto Glycoside

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Chemical Research in Chinese Universities 2001年第Z1期17卷 154-155页

作者： liu hongmin Department of Chemistry Zhengzhou University

2-Oxo derivatives of glycosides, called 2-keto glycosides or glycoside 2-uloses, are biologically important in carbohydrate metabolism and are very useful in synthesis of branched-chain sugars and amino sugars. Very little is known of their chemistry because of the high susceptibility of these compounds to degradation in solution, and in particular their instability to base. Thus it is important to study the reactivities of 2-keto glycosides. In a previous paper, we reported the transformation of 2-keto glycosides in pyridine solution. During the transformation of 2-and 3-keto glycosides, a demethoxylation reaction of the enol intermediate was shown to take place simultaneously with elimination to give hex-1-enopyran-3-ulose.

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Exploration of 5-cyano-6-phenylpyrimidin derivatives containing an 1,2,3-triazole moiety as potent FAD-based LSD1 inhibitors

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Acta Pharmaceutica Sinica B 2020年第9期10卷 1658-1668页

作者： Liying May Haojie Wangy Yinghua You Chaoya Ma Yuejiao liu Feifei Yang Yichao Zheng hongmin liu Collaborative Innovation Center of New Drug Research and Safety Evaluation Henan ProvinceKey Laboratory of Technology of Drug Preparation(Zhengzhou University)Ministry of Education of ChinaKey Laboratory of Henan Province for Drug Quality and EvaluationSchool of Pharmaceutical SciencesZhengzhou UniversityZhengzhou 450001China

Histone lysine specific demethylase 1(LSD1)has become a potential therapeutic target for the treatment of *** and develop novel and potent LSD1 inhibitors is a challenge,although several of them have already entered into clinical ***,for the first time,we reported the discovery of a series of 5-cyano-6-phenylpyrimidine derivatives as LSD1 inhibitors using flavin adenine dinucleotide(FAD)similarity-based designing strategy,of which compound 14 q was finally identified to repress LSD1 with IC50=183 nmol/*** analysis suggested that compound 14 q fitted well into the FAD-binding *** mechanism studies showed that compound 14 q may inhibit LSD1 activity competitively by occupying the FAD binding sites of LSD1 and inhibit cell migration and invasion by reversing epithelial to mesenchymal transition(EMT).Overall,these findings showed that compound14 q is a suitable candidate for further development of novel FAD similarity-based LSD1 inhibitors.

关键词： LSD1 inhibitors Pyrimidine Anticancer Flavin adenine dinucleotide(FAD) Gastric cancer

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