The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform
De-wen Zhao - One of the best experts on this subject based on the ideXlab platform.
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Analysis of snake Rolling force and Torque with changes of thickness depending on unequal Roll radii based on pure aluminum experiments
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2016Co-Authors: Hy Wang, Dh Zhang, Zhenhua Wang, De-wen ZhaoAbstract:An analytical model, in which unequal radii are replaced with an equivalent radius, is creatively proposed to predict the Rolling force and Roll Torque in general case of snake Rolling. With the model, the effects of Roll radius ratio, Roll speed ratio, offset distance between Rolls, reduction and friction coefficient on Rolling forces in hot snake Rolling of aluminum alloy are obtained. Also, the thicknesses of slab are investigated in different zones, which firstly propose the changes of thickness during snake Rolling. Owing to the good agreement with the results measured in experiments and calculated by finite element method and other traditional models, those calculated by the proposed model are verified. The proposed model can be used to predict more accurate theoretical results for snake Rolling force and Torque.
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analysis of broadside Rolling for heavy plate by weighted velocity field and mean yield criterion
Meccanica, 2016Co-Authors: Shun-hu Zhang, Xiao Dong Chen, Ji Xin Hou, De-wen ZhaoAbstract:A new weighted velocity field for broadside Rolling is proposed, in which the effect of double-barrel shape has been taken into account. By using the proposed velocity field and mean yield criterion (or called MY criterion for short), the internal deformation energy rate is obtained. With co-line vector inner-product method, the frictional energy rate between the Roll and the work piece is integrated. Using the double integrals in polar coordinates, the shear energy rate at the entry section is also derived. Ultimately, an analytical solution of Roll Torque and separating force for broadside Rolling is first obtained. The theoretical predictions of Roll Torque and separating force are compared with actual measured data. The result reveals that the proposed solution is appropriate for solving broadside Rolling, and the Roll Torque and separating force are in good agreement with the actual measured ones since the maximum errors are <15.41 %. Moreover, the effects of various Rolling conditions such as thickness reduction, friction factor and shape factor, upon separating force, location of neutral angle, and stress state coefficient are discussed systematically.
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application of hyperbolic sine velocity field for the analysis of tandem cold Rolling
International Journal of Mechanical Sciences, 2016Co-Authors: Jie Sun, Yuanming Liu, Qinglong Wang, Dianhua Zhang, De-wen ZhaoAbstract:Abstract Automatic control systems for tandem cold Rolling are constantly being applied due to consumers’ requirements: good flatness and surface finish, accurate strip thickness, and consistent metallurgical properties. And those requirements are related to accurate prediction of the Roll force directly. A novel analytical approach to predict Roll force in tandem cold Rolling is proposed based on elastic and plastic mechanics. A hyperbolic sine velocity field is firstly proposed to get the required minimum Roll force in plastic deformation zone in this paper. The field, Inscribed Dodecagon (ID) yield criterion and the co-line vector inner product method are applied to integrate the analytical expression of total deformation power functional. The values of Roll Torque, Roll force and stress effective factor are obtained considering the effect of Roll flattening on the Roll force. A good agreement between theoretical predictions of Roll force and other researchers’ models, especially on-line measured Roll force in a tandem cold Rolling plant, verifies that the proposed mathematical model is efficient and stable, and the model can be considered to be applied in cold Rolling. Besides, the effects of Rolling parameters on location of neutral point and stress effective factor are discussed respectively.
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analysis of hot Rolling with simplified weighted velocity field and my criterion
PRICM: 8 Pacific Rim International Congress on Advanced Materials and Processing, 2013Co-Authors: De-wen Zhao, Jianzhao Cao, Shun-hu ZhangAbstract:The weighted velocity field is simplified in analysis of three-dimensional plate hot Rolling. A new yield criterion called mean yield criterion is also used in integral of plastic deformation power of the Rolling. A theoretical solution of Roll Torque and separating force for the Rolling is obtained and the calculated results by the solution are compared with those measured in broadside Rolling on-line. It shows that both the force and Torque calculated are higher than those of measured with assumption of linear distribution of v z along z on entry section. However, taking account of double barrel with parabolic distribution of v z along z, the calculated results are basically coincident with those of measured.
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the calculation of Roll Torque and Roll separating force for broadside Rolling by stream function method
International Journal of Mechanical Sciences, 2012Co-Authors: Shun-hu Zhang, De-wen ZhaoAbstract:Abstract A two-dimensional velocity field for broadside Rolling is proposed by reducing the dual-stream function velocity field. By using the field and the strain vector inner product, an analytical solution of Roll Torque and separating force for broadside Rolling is first obtained. The theoretical predictions of Roll Torque and separating force are compared with actual measured data. The result reveals that the proposed solution is appropriate for solving broadside Rolling, and the Roll Torque and separating force are in good agreement with the actual measured ones since the maximum errors are less than 15%. Moreover, the effects of various Rolling conditions such as thickness reduction, friction factor and shape factor, upon separating force, location of neutral angle, and stress state coefficient are discussed systematically.
H. Bisadi - One of the best experts on this subject based on the ideXlab platform.
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An investigation on the Roll force and Torque fluctuations during hot strip Rolling process
Production & Manufacturing Research, 2014Co-Authors: Bagheripoor, H. BisadiAbstract:Accurate prediction of the Roll separating force and Roll Torque is critical to assuring the quality of the final product. Fluctuation of these parameters during the Rolling process is even more important because of its effects on Rolling setups, geometrical accuracy (especially flatness in strip Rolling), and the uniformity of mechanical and microstructural properties of the Rolled material. The main approach of the present study is a precision analysis of the Roll force and Roll Torque and their instabilities during the Rolling process. In doing so, a coupling multi-variable simulation model for hot strip Rolling was built using non-linear thermo-viscoplastic finite element method. Fluctuations of Roll force and Torque about the steady-state operating point are derived and the effects of main process parameters such as Rolling speed and strip reduction on these instabilities are investigated. To check the validity of the employed model, predicted results are compared with experimental data.
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Application of artificial neural networks for the prediction of Roll force and Roll Torque in hot strip Rolling process
Applied Mathematical Modelling, 2013Co-Authors: Bagheripoor, H. BisadiAbstract:Abstract This paper introduces an artificial neural network (ANN) application to a hot strip mill to improve the model’s prediction ability for Rolling force and Rolling Torque, as a function of various process parameters. To obtain a data basis for training and validation of the neural network, numerous three dimensional finite element simulations were carried out for different sets of process variables. Experimental data were compared with the finite element predictions to verify the model accuracy. The input variables are selected to be Rolling speed, percentage of thickness reduction, initial temperature of the strip and friction coefficient in the contact area. A comprehensive analysis of the prediction errors of Roll force and Roll Torque made by the ANN is presented. Model responses analysis is also conducted to enhance the understanding of the behavior of the NN model. The resulted ANN model is feasible for on-line control and Rolling schedule optimization, and can be easily extended to cover different aluminum grades and strip sizes in a straight-forward way by generating the corresponding training data from a FE model.
Shun-hu Zhang - One of the best experts on this subject based on the ideXlab platform.
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analysis of broadside Rolling for heavy plate by weighted velocity field and mean yield criterion
Meccanica, 2016Co-Authors: Shun-hu Zhang, Xiao Dong Chen, Ji Xin Hou, De-wen ZhaoAbstract:A new weighted velocity field for broadside Rolling is proposed, in which the effect of double-barrel shape has been taken into account. By using the proposed velocity field and mean yield criterion (or called MY criterion for short), the internal deformation energy rate is obtained. With co-line vector inner-product method, the frictional energy rate between the Roll and the work piece is integrated. Using the double integrals in polar coordinates, the shear energy rate at the entry section is also derived. Ultimately, an analytical solution of Roll Torque and separating force for broadside Rolling is first obtained. The theoretical predictions of Roll Torque and separating force are compared with actual measured data. The result reveals that the proposed solution is appropriate for solving broadside Rolling, and the Roll Torque and separating force are in good agreement with the actual measured ones since the maximum errors are <15.41 %. Moreover, the effects of various Rolling conditions such as thickness reduction, friction factor and shape factor, upon separating force, location of neutral angle, and stress state coefficient are discussed systematically.
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analysis of hot Rolling with simplified weighted velocity field and my criterion
PRICM: 8 Pacific Rim International Congress on Advanced Materials and Processing, 2013Co-Authors: De-wen Zhao, Jianzhao Cao, Shun-hu ZhangAbstract:The weighted velocity field is simplified in analysis of three-dimensional plate hot Rolling. A new yield criterion called mean yield criterion is also used in integral of plastic deformation power of the Rolling. A theoretical solution of Roll Torque and separating force for the Rolling is obtained and the calculated results by the solution are compared with those measured in broadside Rolling on-line. It shows that both the force and Torque calculated are higher than those of measured with assumption of linear distribution of v z along z on entry section. However, taking account of double barrel with parabolic distribution of v z along z, the calculated results are basically coincident with those of measured.
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the calculation of Roll Torque and Roll separating force for broadside Rolling by stream function method
International Journal of Mechanical Sciences, 2012Co-Authors: Shun-hu Zhang, De-wen ZhaoAbstract:Abstract A two-dimensional velocity field for broadside Rolling is proposed by reducing the dual-stream function velocity field. By using the field and the strain vector inner product, an analytical solution of Roll Torque and separating force for broadside Rolling is first obtained. The theoretical predictions of Roll Torque and separating force are compared with actual measured data. The result reveals that the proposed solution is appropriate for solving broadside Rolling, and the Roll Torque and separating force are in good agreement with the actual measured ones since the maximum errors are less than 15%. Moreover, the effects of various Rolling conditions such as thickness reduction, friction factor and shape factor, upon separating force, location of neutral angle, and stress state coefficient are discussed systematically.
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Rolling With Simplified Stream Function Velocity and Strain Rate Vector Inner Product
Journal of Iron and Steel Research International, 2012Co-Authors: Shun-hu Zhang, De-wen Zhao, Can-ming Li, Hong-yu Song, Guodong WangAbstract:The dual-stream function velocity field is reduced in order to analyze two-dimensional plate broadside Rolling in roughing. The strain rate vector inner product and integral mean value theorem, as well as co-line vector inner product are used respectively in plastic deformation power, friction losses and shear power. A theoretical solution of Roll Torque and separating force for the Rolling is obtained and the calculated results by the solution are compared with those measured in broadside Rolling on-line. It shows that both the force and Torque calculated are higher than those of measured, but the maximum relative error between them is no more than 11%.
Dongyol Yang - One of the best experts on this subject based on the ideXlab platform.
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UBET analysis of Roll Torque and profile formation during the profile ring-Rolling of rings having rectangular protrusions
Journal of Materials Processing Technology, 1991Co-Authors: Yh Hahn, Dongyol YangAbstract:Abstract An analytical method using the upper-bound elemental technique is proposed for the simulation of Roll Torque and profile formation during profile ring-Rolling. The plastic flow of material during Rolling is described by dividing the whole deforming region at the Roll gap into simple elements of rectangular cross-section and a kinematically admissible velocity field for the three-dimensional material flow in a typical element is derived. Comparing with the experimental results, the calculated Torque estimation shows good agreement, but the prediction of geometrical change is not so satisfactory for some cases. As an engineering tool for theoretical analysis, the present method can be applied effectively to the profile ring-Rolling process.
John G. Lenard - One of the best experts on this subject based on the ideXlab platform.
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an advanced finite element model of the flat cold Rolling process
Primer on Flat Rolling (Second Edition), 2014Co-Authors: John G. LenardAbstract:A finite element model is presented which takes careful account of the three components of the cold, flat Rolling process: the work Roll, the Rolled strip and their interface. The work Roll is treated as an elastic cylinder. The elastic and plastic regions of the Rolled strip are considered. The events at their interface are modelled by a coefficient of friction which depends on the relative velocity between the contacting bodies. The model calculates the Roll separating force, the Roll Torque and the forward slip. These calculations compare well to experimental data. Following the comparisons, the model is used to examine the distributions of the stresses, strains and rates of strain in the work Roll and in the Rolled strip.
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The temperature, Roll force and Roll Torque during hot bar Rolling
Journal of Materials Processing Technology, 1999Co-Authors: Ahmed Said, A.r. Ragab, John G. Lenard, M.abo ElkhierAbstract:Abstract Low-carbon steel bars, 16 mm square, were Rolled in four passes, consisting of a square–diamond–square sequence, to a 10 mm square cross-section. The Roll separating forces and the Roll Torques were determined as a function of the area reduction at entry temperatures of 900, 950, 1000, 1050 and 1100°C. The predictions of the Roll forces and Torques by several models were compared to the experimental data, with mixed success, indicating that further investigations, leading to models of improved accuracy and consistency, should be undertaken. Alternatively, the finite-element method may be used to simulate the process, provided that a good understanding of friction and heat transfer at the contact surfaces is available.
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chapter 4 one dimensional modeling of the flat Rolling process
Mathematical and Physical Simulation of the Properties of Hot Rolled Products, 1999Co-Authors: Maciej Pietrzyk, John G. Lenard, L CserAbstract:This chapter reviews boundary conditions, connected with tribology, and the initial conditions connected with a material's flow strength. In each, the success or failure of the ability of the model to predict the Rolling variables is dependent on the mathematical rigor of the development, as well as on the knowledge and representation of the boundary and initial conditions: the coefficient of friction and the metal's resistance to deformation. An empirical model and several one-dimensional models are presented, all of which are designed to calculate one or more of the Rolling parameters: the Roll separating force, the Roll Torque, the Roll pressure, the power, the temperature rise, and the forward slip. The sensitivity of the predictions of the models to various parameters is also looked into. Finally, the chapter examines the predictive capabilities of the models, in both cold and hot Rolling processes, by comparing them to experimental results.
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thermal mechanical modelling of the flat Rolling process
1991Co-Authors: Maciej Pietrzyk, John G. LenardAbstract:1 Introduction.- 2 Material Properties and Interfacial Friction.- 2.1 Resistance to Deformation.- 2.1.1 Empirical Constitutive Relations for Carbon Steels.- 2.1.2 High Strength Low Alloy Steels.- 2.1.3 Representation of the Results of Compression Tests.- 2.2 Friction in the Flat Rolling Process.- 2.2.1 Friction as a Function of Process and Material Parameters.- 2.2.2 Interfacial Forces in the Roll Gap During Flat Rolling.- 2.2.3 Discussion.- 3 One-Dimensional Models of Flat Rolling.- 3.1 Conventional Models.- 3.1.1 Orowan's Theory.- 3.1.2 Sims' Method.- 3.1.3 Bland and Ford's Technique.- 3.1.4 Ford and Alexander's Method.- 3.1.5 Tselikov's Solution.- 3.2 Refinement of the Conventional Models.- 3.2.1 Derivation of the Basic Equations.- 3.2.2 Roll Deformation.- 3.2.3 Roll Force and Roll Torque.- 3.3 Comparison of Mathematical Models of Flat Rolling.- 3.3.1 Comparison of Assumptions in Various Models.- 3.3.2 Statistical Analysis of Predictive Capabilities.- 3.4 Further Substantiation of the Predictive Capabilities of One- Dimensional Models.- 4 Thermal-Mechanical Finite-Element Modelling of Flat Rolling.- 4.1 Rigid-Plastic Finite-Element Method.- 4.1.1 Description of the Method.- 4.1.2 Boundary Conditions.- 4.1.3 Structure of the Computer Program.- 4.2 Heat Transfer.- 4.2.1 Numerical Solution of the Fourier Equation.- 4.2.2 Steady State Model With Convection.- 4.3 Results of Computations.- 4.3.1 Hot Rolling.- 4.3.2 Cold Rolling.- 4.4 Experimental Substantiation of the Model's Predictions.- 4.4.1 Hot Rolling of Steel.- 4.4.2 Warm Rolling of Aluminium.- 4.4.3 Cold Rolling of Aluminium.- 4.5. Role of the Heat Transfer Coefficient.- 5 The Role of the Shape Coefficient in Modelling of the Flat Rolling Process.- 5.1 Correlation between the Shape Coefficient and Load Parameters.- 5.1.1 The Effect of ? on the Friction Stresses.- 5.1.2 The Effect of ? on Forces and Torques.- 5.2 The Effect of the Shape Coefficient on Strain and Strain Rate Distributions.- 5.2.1 Finite-Element Analysis of Strain Rate Fields for Various Shape Coefficients.- 5.2.2 Efficiency of the Rolling Process.- 6 Conclusions.- References.- Author Index.
