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Development of 2D casting process CAD system based on PDF/image files

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China Foundry 2014年第5期11卷 440-446页

作者： Tang Hongtao Zhou Jianxin Wang Lin Liao Dunming Tao Qing School of mechanical and Electronic Engineering Wuhan University of Technology State Key Laboratory of materials Processing and Die & Mould technology Huazhong University of Science & Technology

A casting process CAD is put forward to design and draw casting process. The 2D casting process CAD, most of the current systems are developed based on one certain version of the AutoCAD system. However the application of these 2D casting process CAD systems in foundry enterprises are restricted because they have several deficiencies, such as being overly dependent on the AutoCAD system, and some part files based on PDF format can not be opened directly. To overcome these deficiencies, for the first time an innovative 2D casting process CAD system based on PDF and image format file has been proposed, which breaks through the traditional research and application notion of the 2D casting process CAD system based on AutoCAD. Several key technologies of this system such as coordinate transformation, CAD interactive drawing, file storage, PDF and image format files display, and image recognition technologies were described in detail. A practical 2D CAD casting process system named HZCAD2D（PDF） was developed, which is capable of designing and drawing the casting process on the part drawing based on the PDF format directly, without spending time on drawing the part produced by AutoCAD system. Final y, taking two actual castings as examples, the casting processes were drawn using this system, demonstrating that this system can significantly shorten the cycle of casting process designing.

关键词： 2D casting process CAD casting process PDF format development of 2D CAD storage of file

Periodic Lattice Porous Structure Produced by Selective Laser Melting:Process,Experiment and Numerical Simulation Analysis

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Computer Modeling in Engineering & Sciences 2020年第10期125卷 77-94页

作者： Jianrui Zhang Min Chi Bo Qian Zhijun Qiu School of mechanical and Power Engineering East China University of Science and TechnologyShanghai200237China School of mechanical MaterialsMechatronic and Biomedical EngineeringUniversity of WollongongWollongongAustralia

To accurately perform the coupled simulation of temperature field and stress field of complex parts and porous structures under the optimal manufacturing process parameters,three kinds of porous structures with different complexity were designed in this ***,ANSYS additive software was used to conduct the stress/deformation simulation of the whole structure under different scanning ***,the optimal scanning strategy for different porous structures was determined,then the experimental preparation was performed,and mechanical properties of compression were tested and *** results show that the elastic modulus and yield strength increase with the increase of pole diameter/wall *** addition,the quasi-static compression simulation of different structures was performed,and the compression performance was analyzed based on the experimental ***,the stress concentration region of different structures was obtained.

关键词： Selective laser melting numerical simulation stress field lattice porous structure

Data-driven prediction of temperature variations in an open cathode proton exchange membrane fuel cell stack using Koopman operator

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Energy and AI 2023年第4期14卷 439-450页

作者： Da Huo Carrie M.Hall mechanical Materialsand Aerospace Engineering DepartmentIllinois Institute of Technology10 West 35th StreetChicago60616ILUnited States

In this study,a novel application of the Koopman operator for control-oriented modeling of proton exchange membrane fuel cell(PEMFC)stacks is *** primary contributions of this paper are:(1)the design of Koopman-based models for a fuel cell stack,incorporating K-fold cross-validation,varying lifted dimensions,radial basis functions(RBFs),and prediction horizons;and(2)comparison of the performance of Koopman-based approach with a more traditional physics-based *** results demonstrate the high accuracy of the Koopman-based model in predicting fuel cell stack behavior,with an error of less than 3%.The proposed approach offers several advantages,including enhanced computational efficiency,reduced computational burden,and improved *** study demonstrates the suitability of the Koopman operator for the modeling and control of PEMFCs and provides valuable insights into a novel control-oriented modeling approach that enables accurate and efficient predictions for fuel cell stacks.

关键词： Proton exchange membrane fuel cell(PEMFC) Data-driven modeling Koopman operator Dynamic modeling Control-oriented modeling Physics-based modeling

Effect of pouring temperature on fractal dimension of primary phase morphology in semi-solid A356 alloy

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中国有色金属学会会刊：英文版 2009年第5期19卷 1098-1103页

作者：刘政毛卫民刘小梅 Jiangxi Nonferrous Metal Processing Engineering Research Center Faculty of mechanical and Electronic Engineering Jiangxi University of Science and Technology School of materials Science and Engineering University of Science and Technology Beijing

The fractal dimensions of primary phase morphology in semi-solid A356 alloy prepared by low superheat pouring and slightly electromagnetic stirring were calculated,and the effect of pouring temperature on fractal dimension of primary phase morphology in semi-solid A356 alloy was *** results indicate that it is feasible to prepare semisolid A356 alloy slurry by low superheat pouring and slightly electromagnetic stirring,and there is an important effect of pouring temperature on the morphology and the grain size of the primary phase in semi-solid A356 alloy,in which the reduction of pouring temperature can obviously improve grain size and shape factor of primary phase in semi-solid A356 alloy under the condition of a certain stirring *** primary phase morphology of semi-solid A356 alloy prepared by low superheat pouring and slightly electromagnetic stirring can be characterized by fractal dimension,and the primary phase morphology obtained by the different processing parameters has the different fractal *** of semi-solid alloy is a course of change in fractal dimension.

关键词： A356合金半固态合金浇注温度分形维数相形态电磁搅拌晶粒尺寸形状因子

Elastocaloric Effect in PbTiO3 Thin Films with 180°Domain Structure:A Phase Field Study

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Chinese Physics Letters 2018年第3期35卷 89-92页

作者：王芳李波欧云刘龙飞王伟 Hunan Provincial Key Laboratory of Health Maintenance for mechanical Equipment Hunan University of Science and Technology School of materials and Engineering Hunan University of Science and Technology School of materials Science and Engineering Xiangtan University China Three Gorges Corporation

The elastocalorie effect of PbTiO3 thin films with 180° domain structure is studied using the phase field method. The influence of external stress σ33, misfit strain μm and domain wall energy on the adiabatic temperature change （ △ Tσ） at room temperature are carried out. The calculation results indicate that ｜△Tσ｜ increases as ｜σ33｜ or ｜μm｜ increases. The largest △ Tσ wlue of--7.81（ is obtained at σ33 = 2 GPa and Um =-0.02. Furthermore, the domain switching behaviors under different gradient coeffcients are different, and finally affect the elastocaloric effect in PTO thin films. These results could provide a guide to choose the substrate and the preparation process in experiments.

关键词： PTO A Phase Field Study Domain Structure Elastocaloric Effect in PbTiO3 Thin Films with 180

A nonsmooth IMC method for mechanical systems with backlash

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控制理论与应用（英文版） 2013年第4期11卷 600-607页

作者： Ruili DONG Yonghong TAN David HE College of mechanical and Electronic technology Shanghai Normal University department of mechanical and Industrial Engineering University of Illinois at Chicago

This paper proposes a discrete-time nonsmooth internal model control （NSIMC） approach for mechanical transmission systems described by so-called sandwich system with backlash. In this method, a dynamic compensator is introduced to compensate for the effect of the input linear subsystem. Thus, the sandwich systems with backlash can be simplified as a pseudo-Hammerstein system with backlash. The corresponding NSIMC strategy is designed to control this system. The design procedure of the controller is presented based on the analysis on the robust stability by considering the model errors involved with the effect of backlash as well as the compensated error of the input linear subsystem. Moreover, as the model is switched among the different operating zones, the robust filters are proposed to guarantee the robust stability and satisfactory control performance of the system.

关键词： Backlash Internal model control Sandwich system Nonsmooth nonlinear systems

Microstructure, mechanical properties and wear resistance of an Al–Mg–Si alloy produced by equal channel angular pressing

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Progress in Natural Science:materials International 2020年第4期30卷 485-493页

作者： Manping Liu Jian Chen Yaojun Lin Zhoulei Xue Hans J.Roven P?l C.Skaret School of materials Science and Engineering Jiangsu University School of materials Science and Engineering Wuhan University of Technology department of materials Science and Engineering Norwegian University of Science and Technology (NTNU)

Microstructure, mechanical properties and wear resistance in an ultrafine-grained Al–Mg–Si alloy fabricated utilizing a combination of equal channel angular pressing(ECAP) and dynamic aging were investigated in this paper. The results indicated that the grain size of the ECAP alloy was significantly refined, i.e., to ～239 nm after three ECAP passes. Meanwhile, the yield and tensile strength of the ECAPed material reached 340 MPa and445 MPa, respectively, while maintaining a significant uniform elongation of 14%. Wear resistance results demonstrated that the wear rate, wear depth and width of the ECAPed material decreased in comparison with the solution-treated(SST) and peak-aged(T6) conditions under a load range of 5–25 N. The adhesive wear that occurs in the undeformed specimens at 10 N does not appear in the ECAPed specimen at the same load, indicating that the ECAPed specimen delay the appearance of more serious wear mechanisms under certain *** cooperative interaction of high density nano-scale β" precipitates and dislocations resulted in a combination of super-high strength and good work hardening ability which suppressed the extension of cracks between the friction layer and the plastic deformation zone. As a consequence, the combination of ECAP and dynamic aging brings a significant improvement for antifriction performance of the 6061 aluminum alloy.

关键词： Al–Mg–Si aluminum Alloy Equal channel angular pressing Dynamic aging mechanical properties Wear resistance Wear mechanism Work hardening rate

Dynamic Recrystallization Behavior of 13%Cr Martensitic Stainless Steel under Hot Working Condition

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Journal of materials Science & technology 2012年第5期28卷 467-473页

作者： G.R.Ebrahimi H.Keshmiri A.R.Maldar A.Momeni Metallurgical and materials Engineering department Ferdowsi University of MashhadMashhad ***Iran department of materials Engineering Sabzevar Tarbiat Moallem UniversitySabzevar ***Iran materials Science and Engineering department Hamedan University of TechnologyHamedan ***Iran

In this study,the effect of hot deformation on martensitic stainless steel was carried out in temperatures between 950 to 1100℃ and strain rates of 0.001,0.01 and 0.1 s *** important dynamic recrystallization parameters,the critical strain and the point of maximum dynamic softening,were derived from strain hardening rate vs stress *** the calculated parameters were used to predict the dynamic recrystallized *** results show that critical stress and strain increase with decreasing deformation temperature and increasing strain *** hot deformation activation energy of the steel is also investigated in the present work with 413 kJ/*** experimental flow curves are in fair agreement with the kinetics of dynamic recrystallization model.

关键词： Hot deformation Dynamic recrystallization Critical strain

CO_2 capture performance of bi-functional activated bleaching earth modified with basic-alcoholic solution and functionalization with monoethanolamine: isotherms, kinetics and thermodynamics

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Journal of Environmental Sciences 2016年第10期28卷 126-137页

作者： Sangobtip Pongstabodee Phuwadej Pornaroontham Nuthapol Pintuyothin Nuttapol Pootrakulchote Nutthavich Thouchprasitchai department of Chemical technology Faculty of Science Chulalongkorn University Center of Excellence on Petrochemical and materials technology Chulalongkorn University

CO2 capture performance of bifunctional activated bleaching earth （ABE） was investigated at atmospheric pressure. The sorbents were characterized by means of X-ray diffraction （XRD）, Brunauer-Emmett-Teller （BET）, Caron-Hydrogen-Nitrogen analysis （CHN）, Fourier transform infrared （FT-IR） and thermal gravimetric analysis （TGA）. The CO2 capacity was enhanced uia basic-modification and monoethanolamine （MEA） loading of the ABE sorbent to obtain a bifunctional surface property. Here, basic-modified calcined ABE with a 30 wt.% MEA loading （SAB-30） showed the highest CO2 capture capacity, but this was decreased with excess MEA loading （〉 30 wt.%）. At a 10% （V/V） initial CO2 concentration feed, the maximum capacity of SAB-30 increased from 2.71 mmol/g at 30~C {without adding moisture to the feed） to 3.3 mmol/g at 50℃ when adding 10% （V/V） moisture to the feed. Increasing the moisture concentration further reduced the maximum CO2 capacity due to the blocking effect of the excess moisture on the sorbent surface. However, SAB-30 could completely capture COg even in a 100% （V/V） initial CO2 concentration feed. A maximum CO2 capacity of 5.7 mmol/g for SAB-30 was achieved at 30℃. Varying the ratio of sorbent weight to total flow rate of the gas stream had no discernible effect on the equilibrium CO2 capture capacity. Avrami＇s equation and Toth＇s isotherm model provided a good fitting for the data and suggested the presence of more than one reaction pathway in the CO2 capture process and the heterogeneous adsorption surface of SAB-30. Thermodynamics studies revealed that CO2 capture on the bifunctional SAB-30 is feasible, spontaneous and exothermic in nature.

关键词： Carbon dioxideCaptureActivated bleaching earthBifunctional surface