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mathematical modeling and simulation of the interface region of a tri-layer composite material,brass-steel-brass,produced by cold rolling

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International Journal of Minerals,Metallurgy and Materials 2009年第2期16卷 189-196页

作者： H. Arabi S.H. Seyedein A. Mehryab B. Tolaminejad School of Metallurgy and Materials Engineering Iran University of Science and TechnologyIUSTNarmakTehranIran

The object of this study was to find the optimum conditions for the production of a sandwich composite from the sheets of brass-steel-brass. The experimental data obtained during the production process were used to validate the simulation program, which was written to establish the relation between the interface morphology and the thickness reduction amount of the composite. For this purpose, two surfaces of a steel sheet were first prepared by scratching brushing before inserting it between two brass sheets with smooth surfaces. Three sheets were then subjected to a cold rolling process for producing a tri-layer composite with various thick- nesses. The sheet interface after rolling was studied by different techniques, and the bonding strength for each rolling condition was determined by peeling test. Moreover, a relation between interfacial bonding strength and thickness reduction was found. The simulation results were compared with the experimental data and the available theoretical models to modify the original simulation program with high application efficiency used for predicting the behavior of the interface under different pressures.

关键词： sandwich composite cold rolling mathematical simulation metallic bonding interface

A study on mathematical simulation of spray forming process

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Baosteel Technical Research 2007年第1期1卷 37-41页

作者： Junfei Fan Yin Zhang Sanbing Ren Hairong Le Shunli Zhao Youduo He Baosteel Research Institute Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China Institute of Metallurgical Engineering UIST Baotou Baotou 014010 China

An integrated approach for modeling the entire spray forming process is presented in this paper, and the program for the simulation is developed. The whole spray forming process can be divided into four calculation processes and the basis for the analysis is the classical k -ε turbulence model which was used to simulate the flow field of gas formed in the chamber. In the atomization model the flow field of gas is coupled with formation, velocity and location of droplet. By means of the above mathematical model, the process of spray forming was simulated.

关键词： spray forming droplets movement mathematical simulation

Application of heat absorption method to reduce macrosegregation during solidification of bearing steel ingot

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Journal of Iron and Steel Research(International) 2022年第12期29卷 1915-1926页

作者： Sheng Yu Long-qiang Zhu Jin-hu Lai Ming-xu Pan Yue-yun Liu Wei-dong Xuan Jiang Wang Chuan-jun Li Zhong-ming Ren State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferrometallurgy and School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Daye Special Steel Co. Ltd.Huangshi 435001HubeiChina

The control of macrosegregation is still a difficult problem for the production of large steel ingots.In order to develop new techniques for producing low-macrosegregation and high-quality steel ingots,the effect of the heat absorption method(HAM)used by the inorganic material rods to cool the liquid steel on the formation of macrosegregation during solidification of a 5-t GCr15SiMn bearing steel ingot was studied using experiment and mathematical simulation.The inorganic material was a mixture of CaF2 and CaO.The levels of macrosegregation in the longitudinal sections of two ingots with and without HAM were compared.Experimental results showed that the application of HAM reduced the positive segregation in the upper part of the ingot and the negative segregation in the lower part.The levels of carbon segregation along the longitudinal centerline and horizontal direction at different heights were all alleviated and the fluctuation of carbon segregation was significantly reduced.The simulation results confirmed that the melting and floating of the inorganic material could carry the sensible heat to the top of the liquid steel quickly.This leads to the acceleration of the cooling rate of the liquid steel,thereby alleviating the level of macrosegregation.

关键词： Large steel ingot Macrosegregation Inorganic material Heat absorption method mathematical simulation

Numerical simulation of temperature fields for weld metal solidification cracking in stainless steels

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China Welding 1999年第1期8卷 58-63页

作者：魏艳红刘仁培董祖珏 Harbin Inst of Technology Harbin China

This paper has analyzed the influences of the heat input of the welding arc, the latent heat of solidification, the fluid flow of liquid metal on the heat conductivity pertaining to the welding solidification crack of stainless steels. As a result, two dimensional heat conduction models with the prescribed heat flux moving along the weld have been developed that can simulate welding arc, convection and radiation heat loss from top and bottom surfaces of the workpiece. Finally, the finite element model was used to analyze and calculate the temperature fields.

关键词： stainless steel solidification cracking temperature field mathematical simulation

simulation of a Walking Robot-E xoskeleton Movement on a Movable Base

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Journal of Artificial Intelligence and Technology 2021年第4期1卷 207-213页

作者： Sergey Jatsun Andrei Malchikov Andrey Yatsun AI Manji Khalil Andres Santiago Martinez Leon Department of Mechanics Mechatronics and RoboticsSouthwest State UniversityKursk 305040Russian Federation

The paper studies the problem of movement of a two-legged walking machine on a movable base.This task is relevant for design rehabilitation and mechanotherapy complexes for people with impaired functions of the musculoskeletal system and presents a mathematical model that allows obtaining the kinematic and dynamic parameters of the movement of the executive units of the device under study.The paper presents a method for planning the trajectory of exoskeleton links,its algorithmic and software implementation.The paper proposes the structure of the automatic link position control system,which ensures the movement of the executive links along a given trajectory.A mathematical apparatus is proposed for studying the dynamics of the controlled movement of the links of the human-machine system of the exoskeleton.The article presents the results of numerical.experiments on the movement of the low-limb exoskeleton leg in the one step mode and analyzes them.

关键词： walking robot mathematical simulation kinematic analysis trajectory planning

CFD simulation on Ethylene Furnace Reactor Tubes

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Petroleum Science 2006年第2期3卷 73-80页

作者： Lan Xingying Xu Chunming Gao Jinsen Zhang Hongmei State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China Department of Petrochemical Engineering Daqing Petroleum Institute Heilongjiang 131400 China

Different mathematical models for ethylene furnace reactor tubes were reviewed. On the basis of these models a new mathematical simulation approach for reactor tubes based on computational fluid dynamics （CFD） technique was presented. This approach took the flow, heat transfer, mass transfer and thermal cracking reactions in the reactor tubes into consideration. The coupled reactor model was solved with the SIMPLE algorithm. Some detailed information about the flow field, temperature field and concentration distribution in the reactor tubes was obtained, revealing the basic characteristics of the hydrodynamic phenomena and reaction behavior in the reactor tubes. The CFD approach provides the necessary information for conclusive decisions regarding the production optimization, the design and improvement of reactor tubes, and the new techniques implementation.

关键词： Reactor tube thermal cracking reaction flow mathematical simulation computational fluid dynamics

PROMOTING SILTATION EFFECTS AND IMPACTS OF HENGSHA EAST SHOAL ON THE YANGTZE RIVER ESTUARY

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Journal of Hydrodynamics 2011年第5期23卷 649-659页

作者： XIE Jun YAN Yi-xin College of Harbor Coastal and Offshore Engineering Hohai University Nanjing 210098 China Shanghai Waterway Engineering Design and Consulting Co. Ltd Shanghai 200120 China

For the Hengsha East Shoal Promoting Siltation Project in the Yangtze River Estuary, this work developed a formula for calculating sediment carrying capacity based on variable coefficients and a mathematical model for suspended sedimentation using variable saturation recovery coefficients. Not only does the model yield good verification, preferably give the hydrodynamics and the sediment concentration, but also reach a good agreement between the simulation results andlux by tide for studying the effect the measured topographical changes in the promoting siltation zone of the Hengsha East Shoal. Moreover, this article proposes a method for examing the net sediment tran- sportation fs of the project of promoting siltation and comparatively analyzes the current siltation of the Hengsha East Shoal and siltation mouth layouts, entrance widths, entrance bottom elevations, and the impact of the South Main Dike on promoting siltation through calculating the net sediment transportation flux by tide over the fixed bed and the direct movable bed numerical simulations. The results are in good agreement with each other, indicating that the method for calculating the net sedi- ment transportation flux by the tide is also useful for assessing the project in promoting siltation. Finally, we use the modeling results to analyze the water and sediment diversion ratios and the changes in silting and scouting in riverbeds and draw the conclusion that the completion of the Hengsha East Shoal Promoting Siltation Project would not adversely affect the Yangtze River Estuary Deepwater Channel Project.

关键词： Hengsha East Shoal promoting siltation effects mathematical simulation sediment diversion ratio net sediment transportation flux

mathematical modeling of fluid flow, heat transfer and inclusion transport in a four strand tundish

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Journal of University of Science and Technology Beijing 2007年第1期14卷 22-26页

作者： Yufeng Wang Guanghua Wen Ping Tang Mingmei Zhu Yuanqing Chen Weizhao Song College of Material Science and Engineering Chongqing University Chongqing 400044China Technical Center Xinjiang Bayi Iron and Steel Co.LtdUrumchi 830022China

mathematical simulation was used for trouble-shooting and optimization. By the mathematical simulation, fluid flow and beat transfer of molten-steel in a four-strand tundish of a billet caster under different conditions （bare tundish and tundish with flow control device） were analyzed, The results showed that （1） the tundish with flow control device （FCD） has an important effect on the fluid pattern and temperature distribution; （2） the unsteady, solving method was used to model the inclusion motions at different time perthds, and it showed that the FCD is advantageous to separate the nonmetallic inclusions. According to the simulation results, the main problem existing in the industry preduction was found, and some helpful rneasurements were executed. Consequently, the large nonmetallic inclusions were separated, and the content of total oxygen was reduced. The qualily of steel was greatly improved.

关键词： mathematical simulation four strand tundish fluid flow temperature distribution inclusion transpori

mathematical model of flow characteristic in multi-strand continuous casting tundishes

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Acta Metallurgica Sinica(English Letters) 2009年第4期22卷 297-307页

作者： Hongwei PAN Shusen CHENG School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

In this paper, the subject of mathematical model is a series of math expressions, which is used to calculate different regions＇ volume fraction and analyze flow characterization in multi-strand tundish. But research about mathematical model for multi-strand tundish is few, and so far, there has been no acknowledged math model for multi- strand tundish to describe its flow characteristic. If Sahai＇s model, which is originally proposed for the case of single-strand tundish （proposed in reference, and this model is widely used in the world）, is applied to describe flow feature in multi-strand tundish, the calculation results would be unreasonable. Based on the data of watermodel experiment results, the sum of each strand＇s dead region＇s volume fraction is bigger than 100%, and this obviously doesn＇T agree with reality; and the value of dead region＇s volume fraction is calculated to be minus according to mathematical simulation results data in another case. What＇s more, Sahai＇s model does not propose the standard of plotting the RTD-curve, and this makes scholars around the world can＇t achieve consensus of views about plotting RTD-curve. And the model doesn＇t consider the bypass flow and can＇t calculate its volume fraction, but bypass flow is critical to tundish metallurgy. And through Sahai＇s model, the calculation result of plug flow region＇s volume fraction is also not reasonable, because the model doesn＇t well describe the essence of plug flow. So these suggest that it is not reliable to apply Sahai＇s single-strand tundish model to multi-strand tundish case. Then a new model is attempted to propose in this paper for your discussion. In the new model, the standard of plotting RTD curve is definitely proposed, and relative calculation method is also proposed; and the feature of dead region is carefully studied and the model proposes a new method to calculate its volume fraction, and the calculation formula about its volume fraction can be adjustable according the actual demand; what＇s more, the new model considers

关键词： Tundish Residual time distribution （RTD） Bypass flow Dead region Water-model mathematical simulation