The Experts below are selected from a list of 4974 Experts worldwide ranked by ideXlab platform
S. M. Hwang - One of the best experts on this subject based on the ideXlab platform.
-
Precision online model for prediction of Strip temperature in hot Strip Rolling
'Maney Publishing', 2019Co-Authors: Jh Lee, W. J. Kwak, Cg Sun, Kh Kim, S. M. HwangAbstract:Investigated via a series of finite element (FE) process simulation is the effect of diverse process variables on some selected non-dimensional parameters characterising the thermomechanical behaviour of the roll and Strip in hot Strip Rolling. Then, on the basis of these parameters, online models are derived for precise prediction of the temperature changes occurring in the bite zone as well as in the interstand zone in a finishing mill. The prediction accuracy of the proposed models is examined through comparison with predictions from a FE process model.X115sciescopu
-
Finite element modeling of thermo-mechanical and metallurgical behavior of type 304 stainless steel in cold Strip Rolling
'Iron and Steel Institute of Japan', 2019Co-Authors: Cg Sun, Yy Lee, Yd Lee, S. M. HwangAbstract:A finite element-based, integrated process model is presented for the coupled analysis of the thermo-mechanical and metallurgical behavior of type 304 stainless steel occurring in the entire tandem mill during cold Strip Rolling. The validity of the proposed model is examined through comparison with measurements. The model's capability of revealing the effect of diverse process parameters is demonstrated through a series of process simulation.X112sciescopu
-
A precision on-line model for the prediction of roll force and roll power in hot-Strip Rolling
'Springer Science and Business Media LLC', 2019Co-Authors: W. J. Kwak, Jh Lee, Yh Kim, S. M. HwangAbstract:Investigated via a series of finite-element (FE) process simulations is the effect of diverse process variables on some selected nondimensional parameters characterizing the thermomechanical behavior of the Strip in hot-Strip Rolling. Then, on the basis of these parameters an on-line model is derived for the precise prediction of roll force and roll power. The prediction accuracy of the proposed model is examined through comparison with predictions from a FE process model and also with measurements.open1115sciescopu
-
FE-based on-line model for the prediction of roll force and roll power in hot Strip Rolling
'Iron and Steel Institute of Japan', 2019Co-Authors: W. J. Kwak, H D Park, Jh Lee, Yh Kim, S. M. HwangAbstract:Investigated via a series of finite element process simulation is the effect of diverse process variables on some selected non-dimensional parameters characterizing the thermo-mechanical behavior of the Strip in hot Strip Rolling. Then, on the basis of these parameters an on-line model is derived for the precise prediction of roll force and roil power, The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model.X1118sciescopu
-
An analytical model for the prediction of Strip temperatures in hot Strip Rolling
'Elsevier BV', 2019Co-Authors: Jae Boo Kim, Jung Hyeung Lee, S. M. HwangAbstract:In hot Strip Rolling, sound prediction of the temperature of the Strip is vital for achieving the desired finishing mill draft temperature (FDT). In this paper, a precision on-line model for the prediction of temperature distributions along the thickness of the Strip in the finishing mill is presented. The model consists of an analytic model for the prediction of temperature distributions in the inter-stand zone, and a semi-analytic model for the prediction of temperature distributions in the bite zone in which thermal boundary conditions as well as heat generation due to deformation are predicted by finite element-based, approximate models. The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model. (C) 2008 Elsevier Ltd. All rights reserved.X1115sciescopu
A K Tieu - One of the best experts on this subject based on the ideXlab platform.
-
effect of surface texture on deformation behavior of asperity in cold metal forming
Advanced Materials Research, 2008Co-Authors: Dongbin Wei, Zhengyi Jiang, Ying De Tang, A K TieuAbstract:It was impossible to obtain the transverse friction along the Strip width in most previous studies of cold Strip Rolling because the surface roughness lays were assumed to be vertical to the Rolling direction. In this study, several types of oblique roughness textures were manufactured on aluminum samples and compression tests were carried out to obtain the effect of different textures on the deformation behavior of surface asperity. Different surface textures resulted in very different peak value of stress. It was found that stress was high and changed dramatically at the initial compression stage but tended to be stable when the total reduction increased. The asperity of which the top angle is 160° showed relatively high resistance to deformation.
-
measurement of the forward slip in cold Strip Rolling using a high speed digital camera
Journal of Mechanical Science and Technology, 2007Co-Authors: A K TieuAbstract:The forward slip in Strip Rolling was defined as the relative difference between the roll surface speed and Strip exit speed. It was always an important parameter because of its significant influence on friction and tension control. In this study a Phantom V3.0 digital high speed image acquisition and motion analysis system was used to record the movement of the roll and the workpiece during Rolling. The pictures captured were analyzed to obtain the speeds of the roll and the workpiece along the roll bite, which then yielded the forward slip. The measurement accuracy has been validated by the mass conservation. The maximum relative error of the forward slip was only 1.6 %. The results have shown that the forward slip increased as the reduction increased for both dry and lubricated Rolling. The roll speed did not change the forward slip in the case of dry Rolling, but the forward slip was significantly reduced with roll speed when lubricated.
-
mixed film lubrication of Strip Rolling using o w emulsions
Tribology International, 2007Co-Authors: P B Kosasih, A K TieuAbstract:A numerical study on the oil concentration effect of O/W emulsion in cold Rolling operating in the mixed film lubrication regime has been carried out. The developed scheme is able to calculate oil concentration at any point within the inlet zone (IZ) and work zone (WZ), Rolling pressure, film thickness, and contact ratio for various Rolling speeds. Hence the intertwined effects of oil concentration of the supplied emulsion and Rolling speed on Strip Rolling are discussed. The study encompasses mixed film regime with speeds S range from 10−5 to 10−3 and supplied emulsion's oil concentration levels λds range from 5% to 90%. The result shows that a moderate rise in oil concentration occurs in the IZ followed by a rapid one at the beginning of the workzone. In most cases, the oil in the emulsion would have been transformed from disperse phase to continuous phase throughout the WZ. Notwithstanding further concentration, which depends on the oil concentration of the supplied emulsion, could still occur in the WZ. The effect of the concentration process is predominantly seen in the development of the lubricant pressure whilst its effect on the total pressure is less pronounced. The analysis of the results suggests that it is possible to lower the emulsion oil concentration without detrimental effects on the Rolling process; and from the analysis of the outlet film thickness, it is shown that the variation of emulsions’ oil concentration could control the exit lubricant film thickness and consequently the Strip surface quality.
-
a thermal analysis of Strip Rolling in mixed film lubrication with o w emulsions
Tribology International, 2006Co-Authors: A K Tieu, P B Kosasih, Ajit R GodboleAbstract:Increase of both roll and Strip surface temperatures can significantly affect a Rolling process, roll conditions and Strip mechanical properties. A comprehensive thermal analysis in cold Rolling, especially in a mixed film regime, is needed to understand how thermal fields develop in roll and Strip during Rolling. It requires a simultaneous solution of the mixed film model for friction in the roll bite and the thermal model for roll and Strip thermal fields. This paper presents a numerical procedure to analyse Strip Rolling process using lubrication with oil-in-water (O/W) emulsions. The thermal model includes the effect of heat generation due to the Strip deformation and frictional shear stress at the asperity contacts. The numerical analysis employs a coupled thermal model and a mixed film lubrication model for calculating the friction and the asperity deformation in the bite. The thermal model considers the initial temperatures of the roll and Strip, temperature rise due to the Strip plastic deformation and friction. While the O/W mixed-film lubrication model takes into account the effect of surface roughness and oil concentration (%vol) of the emulsion. The thermal effect is analysed in terms of Strip surface temperature and roll temperature, which are influenced by Rolling parameters such as reduction, Rolling speed, oil concentration in the emulsion. The results of the parametric study indicate that the effect of oil concentration on the thermal field is relatively small compared to that of reduction ratio and Rolling speed. The reduction ratio increases the maximum interface temperature in the roll bite. In the mixed film regime, Rolling speed also increases the maximum interface temperature and alters the temperature field of the Strip. The numerical procedure was validated against known experimental data and can readily be extended to hot Rolling or used to analyse roll Strip temperature subjected to different cooling system.
-
modelling of work roll edge contact in thin Strip Rolling
Journal of Materials Processing Technology, 2004Co-Authors: Zhengyi Jiang, A K Tieu, Hongtao Zhu, Weihua SunAbstract:Abstract Work roll contact at the edges forms a new deformation feature in cold Strip Rolling. In this paper, a modified influence function method is developed to analyse the cold Rolling of thin Strip when the work roll edges contact. The effect of Strip width on specific force such as Rolling force, intermediate force and edge contact force, length of edge contact, shape and profile of the thin Strip is discussed. The effect of transverse friction variation on the shape and profile of Strip is also considered. Results show that the transverse friction has a significant influence on the shape and profile of the thin Strip.
Zhengyi Jiang - One of the best experts on this subject based on the ideXlab platform.
-
fem analysis of profile control capability during Rolling in a 6 high cvc cold Rolling mill
Advanced Materials Research, 2014Co-Authors: Ke Zhi Linghu, Zhengyi Jiang, Jingwei Zhao, Yong Qiang WangAbstract:A 3D elastic-plastic finite element method (FEM) model of cold Strip Rolling for 6-high continuous variable crown (CVC) Rolling mill was developed. The Rolling force distributions were obtained by the internal iteration processes. The calculated error has been significantly reduced by the developed model. the absolute error between the simulated results and the actual values is obtained to be less than 10μm, and relative error is less than 1%. The developed model is significant in investigating the profile control capability of the CVC cold Rolling mill in terms of work roll bending, intermediate roll bending and intermediate roll shifting.
-
thin Strip profile control capability of roll crossing and shifting in cold Rolling mill
Materials Science Forum, 2013Co-Authors: Abdulrahman Aljabri, Zhengyi Jiang, Xiao Dong Wang, Hasan TibarAbstract:ContRolling cold Strip profile is a difficult and significant problem has been found in industry during thin Strip Rolling. At present choosing the new type of Strip Rolling mill is the one of main methods to control the Strip shape quality in cold Rolling. The influences of Rolling process parameters such as the work roll cross angle and work roll shifting on the Strip shape and profile of thin Strip are recognised throughout this study. The results show that the roll crossing and shifting is efficient way to control the Strip shape. The increase of the work roll crossing angle would lead to improve the Strip profile significantly by decreasing the exit Strip crown and edge drop. The Strip profile would be enhanced if the axial roll shifting was increased. Moreover, the total Rolling force was analysed in detail by changing the roll cross angle and axial shifting roll.
-
analysis of friction and surface roughness effects on edge crack evolution of thin Strip during cold Rolling
Tribology International, 2011Co-Authors: Haibo Xie, Zhengyi Jiang, W. Y. Daniel YuenAbstract:Abstract Experimental investigation and mechanical analysis have been carried out to study the edge crack formation during cold Strip Rolling using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The effects of friction and surface roughness on edge crack initiation and growth rate have been discussed. Friction leads to an increase in fracture loads and decreasing the friction coefficient is effective in preventing the microcracks. Surface roughness variation along the Strip width contributes to stress distribution and inhibits crack nucleation. The findings reveal that the behaviour of crack evolution is influenced by fracture surface roughness as well as Rolling friction.
-
Modelling of the effect of friction on cold Strip Rolling
Journal of Materials Processing Technology, 2008Co-Authors: Zhengyi Jiang, Anh Kiet Tieu, Shangwu Xiong, Jane Q WangAbstract:Friction is the reason for the process of Rolling to actually take place, and it plays an important role in determining the Rolling mechanics and deformation distributions of the Strip. At the interface between the roll and Strip, friction has a significant influence on the dimensional accuracy and Strip surface quality. This paper presents the modelling of cold Strip Rolling taking into account the friction along the Strip Rolling and transverse directions. A 3D rigid plastic finite element method considering slightly compressible material, and an influence function method were employed, respectively, to analyse the cold Strip Rolling, and simulation results show that the friction in both directions has a significant effect on the Rolling mechanics, Strip shape and profile. Variation of the transverse friction affects the Strip edge drop, but the friction variation along the Rolling direction may affect the central and edge buckles of the Strip. The calculated Rolling forces are in good agreement with the measured values.
-
effect of surface texture on deformation behavior of asperity in cold metal forming
Advanced Materials Research, 2008Co-Authors: Dongbin Wei, Zhengyi Jiang, Ying De Tang, A K TieuAbstract:It was impossible to obtain the transverse friction along the Strip width in most previous studies of cold Strip Rolling because the surface roughness lays were assumed to be vertical to the Rolling direction. In this study, several types of oblique roughness textures were manufactured on aluminum samples and compression tests were carried out to obtain the effect of different textures on the deformation behavior of surface asperity. Different surface textures resulted in very different peak value of stress. It was found that stress was high and changed dramatically at the initial compression stage but tended to be stable when the total reduction increased. The asperity of which the top angle is 160° showed relatively high resistance to deformation.
Kozo Osakada - One of the best experts on this subject based on the ideXlab platform.
-
Simulation of plane-strain Rolling by the rigid-plastic finite element method
International Journal of Mechanical Sciences, 2003Co-Authors: Ken-ichiro Mori, Kozo OsakadaAbstract:Abstract The rigid-plastic finite element method for a slightly compressible material is applied to steady and non-steady state Strip Rolling. Solutions for some technical problems using a finite element analysis for Rolling process are given. Stress and strain distributions in steady state plane-strain Strip Rolling under the condition of a constant coefficient of friction are calculated for work-hardening and non-hardening materials. The calculated distribution of roll pressure exhibits a peak at the entry which does not appear in the analysis by the slab method. Non-steady state deformation of the front and tail ends is also analysed. The calculated end shapes are in good agreement with the experimental ones for aluminium Strip.
R Mei - One of the best experts on this subject based on the ideXlab platform.
-
initial guess of rigid plastic finite element method in hot Strip Rolling
Journal of Materials Processing Technology, 2009Co-Authors: Guibao Zhang, Suju Zhang, Haiqu Zhang, Jing Liu, R MeiAbstract:Although the rigid plastic finite element method (RPFEM) is extremely efficient and particularly suitable for analyzing the Strip Rolling, it is unavailable for online application due to the large computational time. During iterative solution of RPFEM, the convergence speed is greatly determined by the initial guess. In this paper, three different initial guesses are constructed through Engineering Method, G Functional and Neural Network, respectively. Especially, the back propagation neural network model for predicting the relative velocity field (nodal velocities/roll speed) is trained from huge amounts of RPFEM results. Whereafter, the initial guess is calculated by multiplying the predicted relative velocity field by the roll speed. The numerical examples of seven passes hot Strip Rolling are provided to show the solution efficiency and the accuracy of RPFEM code in the cases of different initial guess. Compared with other two methods, the Neural Network has the remarkable advantages to reduce the CPU time and the iterations of RPFEM code. From the numerical results, it is found that the CPU time, stability and the accuracy of RPFEM code in the initial guess by the Neural Network can meet the requirements of online control completely in hot Strip Rolling.
