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Model for the Whole Roller Leveling Process of Plates with Random Curvature Distribution Based on the Curvature Integration Method

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Chinese Journal of Mechanical Engineering 2019年第3期32卷 145-155页

作者： Ben Guan Chao Zhang yong zang Yuan Wang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China

A model based on the curvature integration method has been applied in an online plate leveling system. However, there are some shortcomings in the current leveling models. On the one hand, the models cannot deal with the leveling process of plates with a random curvature distribution. On the other hand, the current models are suitable only for stable leveling processes and ignore the biting in and tailing out stages. This study presents a new plate-leveling model based on the curvature integration method, which can describe the leveling process of plates with random curvature distribution. Further, the model is solved in two cases in order to take the biting in and tailing out stages into consideration. The proposed model is evaluated by comparing with a plate leveling experiment. Finally, the leveling process of a plate with a wave bent is studied using the proposed model. It is found that the contact angles vary greatly during the biting in and tailing out stages. However, they are relatively steady during the 5 roller leveling stage. In addition, the contact angle of roller No. 2 is the smallest, which is close to 0. Roller leveling can effectively eliminate bending in the plate, but there are regions in the head and tail of the plate, where roller leveling is not effective. The non-leveling region length is about 2 times that of the roller space. This study proposes a quasi-static plate-leveling model, which makes it possible to analyze the dynamic straightening process using a curvature integration method. It also makes it possible to analyze the straightening process of a plate with random curvature distribution.

关键词： Leveling Curvature integration method Curvature Contact angle Deflection

Tandem Strip Mill's Multi-parameter Coupling Dynamic Modeling Based on the Thickness Control

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Chinese Journal of Mechanical Engineering 2015年第2期28卷 353-362页

作者： PENG Yan ZHANG Yang SUN Jianliang zang yong National Engineering Research Center for Equipment and Technology of Cold Rolling Strip Yanshan University School of Mechanical Engineering University of Science and Technology Beijing

The rolling process is determined by the interaction of a number of different movements,during which the relative movement occurs between the vibrating roll system and the rolled piece,and the roll system＇s vibration interacts with the strip＇s deformation and rigid *** many parameters being involved leads to a complex mechanism of this coupling *** testing and analyzing the vibration signals of the mill in the rolling process,the rolling mill＇s coupled model is established with comprehensive consideration of the coupling interaction between the mill＇s vertical vibration,its torsional vibration and the working roll＇s horizontal vibration,and vibration characteristics of different forms of rolling mill＇s vibration are analyzed under the coupling *** comprehensive attention to the relationship between the roll system,the moving strip and the rolling parameters＇dynamic properties,and also from the strip thickness control point of view,further research is done on the coupling mechanism between the roll system＇s movement and the moving strip＇s characteristics in the rolling *** a result,the law of inertial coupling and the stiffness coupling effect caused by different forms of the roll system＇s vibration is determined and the existence of nonlinear characteristics caused by the elastic deformation of moving strip is also ***,a multi-parameter coupling-dynamic model is established which takes the tandem strip mill as its research object by making a detailed kinematics analysis of the roll system and using the principle of virtual *** coupling-dynamic model proposes the instruction to describe the roll system＇s movement,and analyzes its dynamic response and working stability,and provides a theoretical basis for the realization of the strip thickness＇dynamic control.

关键词： tandem strip mill dynamic characteristics moving strip roll system

Roll System and Stock's Multi-parameter Coupling Dynamic Modeling Based on the Shape Control of Steel Strip

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 614-624页

作者： Yang ZHANG Yan PENG Jianliang SUN yong zang National Engineering Research Center for Equipment and Technology of Cold Rolling Strip Yanshan University School of Mechanical Engineering University of Science and Technology Beijing

The existence of rolling deformation area in the rolling mill system is the main characteristic which dis- tinguishes the other machinery. In order to analyze the dynamic property of roll system＇s flexural deformation, it is necessary to consider the transverse periodic movement of stock in the rolling deformation area which is caused by the flexural deformation movement of roll system simul- taneously. Therefore, the displacement field of roll system and flow of metal in the deformation area is described by kinematic analysis in the dynamic system. Through intro- ducing the lateral displacement function of metal in the deformation area, the dynamic variation of per unit width rolling force can be determined at the same time. Then the coupling law caused by the co-effect of rigid movement and flexural deformation of the system structural elements is determined. Furthermore, a multi-parameter coupling dynamic model of the roll system and stock is established by the principle of virtual work. More explicitly, the cou- pled motion modal analysis was made for the roll system. Meanwhile, the analytical solutions for the flexural defor- mation movement＇s mode shape functions of rolls are discussed. In addition, the dynamic characteristic of the lateral flow of metal in the rolling deformation area has been analyzed at the same time. The establishment ofdynamic lateral displacement function of metal in the deformation area makes the foundation for analyzing the coupling law between roll system and rolling deformation area, and provides a theoretical basis for the realization of the dynamic shape control of steel strip.

关键词： Roll system Rolling deformation area Coupling dynamic model Mode shape function - Lateraldisplacement function

An interface shear damage model of chromium coating/steel substrate under thermal erosion load

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Defence Technology（防务技术） 2021年第2期17卷 405-415页

作者： Xiao-long Li yong zang yong Lian Min-yu Ma Lei Mu Qin Qin School of Mechanical Engineering University of Science and Technology BeijingBeijing100083China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory for Corrosion Erosion and Surface TechnologyBeijing100083China

The Cr-plated coating inside a gun barrel can effectively improve the barrel’s erosion resistance and thus increase the service ***,due to the cyclic thermal load caused by high-temperature gunpowder,micro-element damage tends to occur within the Cr coating/steel substrate interface,leading to a gradual deterioration in macro-mechanical properties for the material in the related *** order to mimic this cyclic thermal load and,thereby,study the thermal erosion behavior of the Cr coating on the barrel’s inner wall,a laser emitter is utilized in the current *** the help of in-situ tensile test and finite element simulation results,a shear stress distribution law of the Cr coating/steel substrate and a change law of the interface ultimate shear strength are *** have shown that the Cr coating/steel substrate interface’s ultimate shear strength has a significant weakening effect due to increasing *** this study,the interfacial ultimate shear strength decreases from 2.57 GPa(no erosion)to 1.02 GPa(laser power is 160 W).The data from this experiment is employed to establish a Cr coating/steel substrate interface shear damage *** this model is used to predict the flaking process of Cr coating by finite element *** simulation results show that the increase of coating crack spacing and coating thickness will increase the service life of gun barrel.

关键词： Cr coating/steel substrate Thermal erosion Finite element simulation Ultimate shear strength Interface shear damage model

Non-linear Dynamics of Inlet Film Thickness during Unsteady Rolling Process

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Chinese Journal of Mechanical Engineering 2016年第3期29卷 522-530页

作者： FU Kuo zang yong GAO Zhiying QIN Qin WU Diping School of Mechanical Engineering University of Science and Technology Beijing

The inlet film thickness directly affects film and stress distribution of rolling interfaces. Unsteady factors, such as unsteady back tension, may disturb the inlet film thickness. However, the current models of unsteady inlet film thickness lack unsteady disturbance factors and do not take surface topography into consideration. In this paper, based on the hydrodynamic analysis of inlet zone an unsteady rolling film model which concerns the direction of surface topography is built up. Considering the small fluctuation of inlet angle, absolute reduction, reduction ratio, inlet strip thickness and roll radius as the input variables and the fluctuation of inlet film thickness as the output variable, the non-linear relationship between the input and output is discussed. The discussion results show that there is 180° phase difference between the inlet film thickness and the input variables, such as the fluctuant absolute reduction, the fluctuant reduction ratio and non-uniform inlet strip thickness, but there is no phase difference between unsteady roll radius and the output. The inlet angle, the steady roll radius and the direction of surface topography have significant influence on the fluctuant amplitude of unsteady inlet film thickness. This study proposes an analysis method for unsteady inlet film thickness which takes surface topography and new disturbance factors into consideration.

关键词： cold rolling lubricant film inlet zone surface topography unsteady non-linear

Preparation of CaO-Al_2O_3-SiO_2 system glass from molten blast furnace slag

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 169-174页

作者： Ying Xu yong-zang Zhang Lin-yan Hou Xiang Lu College of Material Science and Engineering Hebei United University Xingtai Iron and Steel Co. Ltd.

To use the potential heat of molten blast furnace slag completely, a CaO-Al2O3-SiO2 system glass （MSG） was prepared from the molten industrial slag. The corresponding method proposed in this study utilized both slag and its potential heat, improving the production rate and avoiding the environmental pollution. Using appropriate techniques, an MSG with uniform color and superior performances was produced. Based on the experimental results and phase diagram, the chemical composition of MSG by mass is obtained as follows：CaO 27%-33%, SiO2 42%-51%, Al2O3 11%-14%, MgO 6%-8%, and Na2O＋K2O 1%-4%. Thermodynamic processes of MSG preparation were analyzed, and the phases and microstructures of MSG were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results show that alkali metal oxides serve as the fluxes, calcium oxide serves as the stabilizer, and alumina reinforces the Si-O network. XRD and SEM analyses show that, the prepared MSG displays the glass-feature patterns, the melting process is more complete, and the melt viscosity is lowered with an increase in calcium oxide content;however, a continuous increase in slag content induces the crystalli-zation of glass, leading to the formation of glass subphase. The optimum content of molten slag in MSG is 67.37wt%. With respect to bend-ing strength and acid/alkali resistance, the performance of MSG is better than that of ordinary marble.

关键词： industrial wastes slag glass thermodynamics microstructure waste utilization heat recovery

Stability analysis of unsaturated soil slope during rainfall infiltration using coupled liquid-gas-solid three-phase model

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Water Science and Engineering 2016年第3期9卷 183-194页

作者： Dong-mei Sun Xiao-min Li Ping Feng yong-ge zang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University

Generally, most soil slope failures are induced by rainfall infiltration, a process that involves interactions between the liquid phase, gas phase,and solid skeleton in an unsaturated soil slope. In this study, a loosely coupled liquid-gas-solid three-phase model, linking two numerical codes,TOUGH2/EOS3, which is used for water-air two-phase flow analysis, and FLAC^(3D), which is used for mechanical analysis, was established. The model was validated through a documented water drainage experiment over a sandy column and a comparison of the results with measured data and simulated results from other researchers. The proposed model was used to investigate the features of water-air two-phase flow and stress fields in an unsaturated soil slope during rainfall infiltration. The slope stability analysis was then performed based on the simulated water-air two-phase seepage and stress fields on a given slip surface. The results show that the safety factor for the given slip surface decreases first, then increases, and later decreases until the rainfall stops. Subsequently, a sudden rise occurs. After that, the safety factor decreases continually and reaches its lowest value, and then increases slowly to a steady value. The lowest value does not occur when the rainfall stops, indicating a delayed effect of the safety factor. The variations of the safety factor for the given slip surface are therefore caused by a combination of pore-air pressure, matric suction, normal stress, and net normal stress.

关键词： Coupled liquid-gas-solid three-phase model Pore-air pressure Unsaturated soil slope stability Rainfall infiltration

Cytological and molecular characteristics of delayed spike development in wheat under low temperature in early spring

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The Crop Journal 2022年第3期10卷 840-852页

作者： Xurun Yu Yufei Jiang Huihui Yao Liping Ran yong zang Fei Xiong Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Key Laboratory of Crop Cultivation and Physiology Agricultural College of Yangzhou UniversityCo-Innovation Center for Modern Production Technology of Grain CropsYangzhou UniversityYangzhou 225009JiangsuChina Yangzhou University Guangling College Yangzhou 225000JiangsuChina

Low temperature in early spring impairs wheat growth and grain ***,little is known about the cytological and molecular mechanisms underlying low temperature regulation of wheat spike *** observation and transcriptome sequencing of wheat spikes under low temperature were *** temperature slowed spike development,reduced the yield-component parameters of wheat spikes at the harvest stage,delayed the formation of lateral spikelets and tissue development,and induced the early differentiation of terminal *** temperature increased the content of abscisic acid and caused the upregulation of genes in the abscisic acid signaling pathway,including those encoding PP2 Cs,Sn RK2 s,and b ZIP transcription *** temperature also induced the upregulation of 33 cold-responsive genes involved in wheat response to low-temperature stress and regulation of abscisic acid biosynthesis and metabolism of other *** wheat spike adapted to cold conditions by changing the expression levels of genes involved in spike morphogenesis,including the transcription-factor genes MADS6,ERF4,ERF78,WOX6,and *** findings suggest that low temperature in early spring delays wheat spike development by increasing abscisic acid content or affecting the expression of genes involved in morphogenesis.

关键词： Development Low temperature Spike Transcriptome Wheat

Substantial hepatic necrosis is prognostic in fulminant liver failure

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World Journal of Gastroenterology 2017年第23期23卷 4303-4310页

作者： Paul Ndekwe Marwan S Ghabril yong zang Steven A Mann Oscar W Cummings Jingmei Lin Department of Pathology and Laboratory Medicine Indiana University School of Medicine Department of Internal Medicine Division of Gastroenterology and HepatologyIndiana University School of Medicine Department of Biostatistics Indiana University School of Medicine

To evaluate if any association existed between the extent of hepatic necrosis in initial liver biopsies and patient ***-seven patients with fulminant liver failure, whose liver biopsy exhibited substantial necrosis, were identified and included in the study. The histological and clinical data was then analyzed in order to assess the relationship between the extent of necrosis and patient survival, with and without liver transplantation. The patients were grouped based on the etiology of hepatic necrosis. Each of the etiology groups were then further stratified according to whether or not they had received a liver transplant post-index biopsy, and whether or not the patient *** core tissue length ranged from 5 to 44 mm with an average of 23 mm. Causes of necrosis included 14 autoimmune hepatitis, 10 drug induced liver injury (DILI), 9 hepatitis virus infection, and 4 unknown origin. Among them, 11 showed submassive (26%-75% of the parenchymal volume) and 26 massive (76%-100%) necrosis. Transplant-free survival was worse in patients with a higher extent of necrosis (40%, 71.4% and 100% in groups with necrosis of 76%-100%, 51%-75% and 26%-50%, respectively). Additionally, transplant-free survival rates were 66.7%, 57.1%, and 25.0% in groups of autoimmune hepatitis, DILI, and viral hepatitis, respectively. Even after liver transplantation, the survival rate in patients as a result of viral hepatitis remained the lowest (80%, 100%, and 40% in groups of autoimmune hepatitis, DILI, and viral hepatitis, respectively).CONCLUSIONAdequate liver biopsy with more than 75% necrosis is associated with significant transplant-free mortality that is critical in predicting survival.

关键词： Submassive necrosis Massive necrosis Fulminant liver failure Liver transplantation Biopsy Histopathology