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DEVELOPMENT OF computer simulation SOFTWAREON PHASE TRANSFORMATION DURING QUENCHING

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Acta Metallurgica Sinica(English Letters) 2000年第2期13卷 618-622页

作者： L. Chen, W. Xia and X. J. Chen Department of Materials Science and Engineering, Nanchang Institute of Aeronautical Technology, Nanchang 330034, China

A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercooled austenite are described by cubic spline functions. This software is possess of a good graphic interface of Windows style, can simulate the whole process in austenite decomposition during continuous cooling. If the cooling rate was given, the fraction of various microstructures transformed of austenite decomposition during continuous cooling at any temperature can be calculated. The simulation results are checked with the quenching experiment of 45 steel. The results indicate that the simulation results are comparatively close to the experimental results.

关键词： quenching phase transformation computer simulation software

computer simulation OF GRAIN BOUNDARY SEGREGATION BEHAVIOR AND MECHANISMS OF STRENGTHENING OF Mg IN Ni-BASED SUPERALLOYS

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International Journal of Minerals,Metallurgy and Materials 1995年第2期9卷 108+84-91页

作者：陈国良葛红林北京科技大学新金属国家重点实验室

This paper used EAM and static relaxation method to simulate the grain boundary segregation behavior of Mg in Ni-based superalloys. The results offer a better understanding in the strengthening mechanism of Mg addition in superalloys. The segregation of Mg increases the grain boundary cohesive bond and the vacancy formation energy, and decreases the mobility of grain boundary dislocation. It results in the retardation of creep voids initiation and growth.

关键词： Mg in Superalloys Grain boundary segregation superalloy computer simulation

Best bone of acetabulum for cup component placement in Crowe types Ⅰto Ⅲ dysplastic hips:a computer simulation study

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Chinese Medical Journal 2019年第23期132卷 2820-2826页

作者： Lin-Li Zheng Yang-Yang Lin Xiao-Yan Zhang Qian-Hui Ling Wei-Ming Liao Pei-Hui Wu Department of Joint Surgery the First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong 510080China Department of Rehabilitation Medicine the Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong 510655China College of computer Science&Software Engineering Shenzhen UniversityShenzhenGuangdong 518060China Zhongshan Medical School Sun Yat-sen UniversityGuangzhouGuangdong 510080China

Background:During cup implantation,vertical height of the cup center(V-HCC)should be precisely controlled to achieve sufficient bone-cup coverage(BCC).Our study aimed to investigate the acetabular bone stock and the quantitative relationship between V-HCC and BCC in Crowe types Ⅰto Ⅲ ***:From November 2013 to March 2016,pelvic models of 51 patients(61 hips)with hip dysplasia were retrospectively reconstructed using a computer *** height and doom thickness were measured on the mid-acetabular coronal cross section.V-HCC was defined as the vertical distance of cup rotational center to the interteardrop line(ITL).In the cup implantation simulation,the cup was placed at the initial preset position,with a V-HCC of 15 mm,and moved proximally by 3-mm *** each level,the BCC was automatically calculated by *** of variance and Kruskal-Wallis test were used to compare the differences between ***:There were no significant between-group differences in maximum thickness of the acetabular doom;however,peak bone stock values were obtained at heights of 41^3±5.14 mm(Crowe typeⅠ),47.58±4.10 mm(Crowe type Ⅱ),and 55.78±3.64 mm(Crowe type Ⅲ)above the *** 15 mm of V-HCC,median BCC was 78%(75-83%)(Crowe type Ⅰ),74%(66-71%)(Crowe type Ⅱ),and 61%(57-68%)(Crowe type Ⅲ).To achieve 80%of the BCC,the median V-HCC was 16.27(15.00-16.93)mm,18.19(15.01-21.53)mm,and 24.13(21.02-28.70)mm for Crowe typesⅠ,Ⅱ,and Ⅲ hips,***:During acetabular reconstruction,slightly superior placement with V-HCC<25 mm retained sufficient bone coverage in CroweⅠto Ⅲ hips.

关键词： computer simulation Congenital dysplasia Hip Three-dimensional image Total-hip replacement

Application of the computer simulation Technique to Developing EFI Engine

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Journal of Beijing Institute of Technology 2000年第2期9卷 205-210页

作者：张付军赵长禄黄英葛蕴珊孙业保北京理工大学车辆工程学院北京100081

The application of computer simulation technique to electronic controlled fuel injection(EFI) engine was studied to increase the development speed and improve the overall performance of the engine and car. On the basis of an EFI system developed by ourselves, the simulation model of the initial control data and engine operation points during a driving cycle and the car performance pridiction model were established. This method was applied to a mini car. The experiment showed that the simulated control data has good accuracy; and the engine test points and car performances obtained by simulation are useful for the matching of EFI system with gasoline engine and the development speed is increased.

关键词： computer simulation electronic-controlled fuel injection (EFI) gasoline engine

We Are Living in a computer simulation

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Journal of Modern Physics 2016年第10期7卷 1210-1227页

作者： Ding-Yu Chung Utica MI USA

This paper posits that we are living in a computer simulation to simulate physical reality which has the same computer simulation process as virtual reality (computer-simulated reality). The computer simulation process involves the digital representation of data, the mathematical computation of the digitized data in geometric formation and transformation in space-time, and the selective retention of events in a narrative. Conventional physics cannot explain physical reality clearly, while computer-simulated physics can explain physical reality clearly by using the computer simulation process consisting of the digital representation component, the mathematical computation component, and the selective retention component. For the digital representation component, the three intrinsic data (properties) are rest mass-kinetic energy, electric charge, and spin which are represented by the digital space structure, the digital spin, and the digital electric charge, respectively. The digital representations of rest mass and kinetic energy are 1 as attachment space for the space of matter and 0 as detachment space for the zero-space of matter, respectively, to explain the Higgs field, the reverse Higgs field, quantum mechanics, special relativity, force fields, dark matter, and baryonic matter. The digital representations of the exclusive and the inclusive occupations of positions are 1/2 spin fermion and integer spin boson, respectively, to explain spatial translation by supersymmetry transformation and dark energy. The digital representations of the allowance and the disallowance of irreversible kinetic energy are integral electric charges and fractional electric charges, respectively, to explain the confinements of quarks and quasiparticles. For the mathematical computation component, the mathematical computation involves the reversible multiverse and oscillating M-theory as oscillating membrane-string-particle whose space-time dimension (D) number oscillates between 11D an

关键词： computer simulation Physical Reality Virtual Reality Digital computer computer-Simulated Physics Digital Representation Selective Retention M-Theory Space Structure Higgs Field Reverse Higgs Field Fractional Electric Charge Spin Multiverse Cosmology Force Fields Cyclic Universe

Atomic-scale computer simulation for early precipitation process of Ni75 Alx V25-x alloy with intermediate Al composition

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Progress in Natural Science:Materials International 2005年第4期 64-70页

作者： ZHAO Yuhong 1*, JU Dongying 2, CHEN Zheng 3* and HOU Hua 1(1. College of Material Science & Engineering, China North University, Taiyuan 030051, China 2. Department of Mechanical Engineering, Saitama Institute of Technology, Okabe, Saitama 369 0239, Japan 3. Colledge of Materials Science & Engineering, Northwestern Polytechnical University, Xi'an 710072, China)

The microscopic phase field approach is applied to model the early precipitation process of Ni 75 Al x V 25- x alloy. Without any prior assumptions, this model can be used to simulate the temporal evolution of arbitrary morphologies and microstructures on atomic scale. By simulating the atomic pictures, and calculating the order parameters and volume fraction of the θ (Ni 3V) and γ′ (Ni 3Al) ordered phases, we study Ni 75 Al x V 25- x alloys with Al composition of 0.05, 0.053 and 0.055 (atom fraction). Our calculated results show that, for these alloys, θ and γ′ phases precipitate at the same time; with the increase of Al content, the amount of γ′ phase increases and that of θ phase decreases; the precipitation characteristic of γ′ phase transforms from Non Classical Nucleation and Growth (NCNG) to Congruent Ordering + Spinodal Decomposition (CO+SD) gradually; otherwise, the precipitation characteristic of θ phase transforms from Congruent Ordering + Spinodal Decomposition (CO+SD) to Non Classical Nucleation and Growth (NCNG) mechanism gradually. Both θ and γ′ phases have undergone the transition process of mixture precipitation mechanism characterized by both NCNG and CO+SD mechanisms. No incontinuous transition of precipitation mechanism has been found.

关键词： computer simulation early precipitation mechanism phase field model Ni75Alx V25-x alloy.

Atomic-scale computer simulation for early precipitation process of Ni75 Al10 V15 alloy

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Progress in Natural Science:Materials International 2004年第3期 49-54页

作者： ZHAO Yuhong*, CHEN Zheng, WANG Yongxin and LU Yanli (Department of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China)

The kinetic model for a ternary system is introduced based on the microscopic diffusion form of the phase field equations for a binary alloy. The equation is solved in the reciprocal space. This model is used to investigate the early precipitation process of Ni 75 Al 10 V 15 by simulating the atomic pictures of the two ordered phases and calculating the order parameters of γ ′(Ni 3Al) phase. simulation results show that the γ ′ ordered phases precipitate from the disordered matrix by a non classical nucleation mechanism, and the nonstoichiometric γ ′ ordered phase appears first and then transforms into the stoichiometric one. Clusters of V atoms appear at the γ ′ phase boundaries followed by the formation of the nonstoichiometric θ ordered phase. The farther the location from γ ′ phase boundary is, the lower the order degree of θ phase is. There exist two kinds of DO 22 ordered domains: a horizontal one and a vertical one, related to their adjacent γ ′ phase boundaries. The model could describe the atomic ordering and composition clustering simultaneously, and any a priori assumption about the new phase structure and precipitation mechanism etc. is unnecessary.

关键词： early precipitation process computer simulation Ni 75 Al 10 V 15 alloy.

A Study on a Wire Tension Adaptive Control System of a Multi-wire Saw in computer simulation

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International Journal of Plant Engineering and Management 2011年第3期16卷 170-177页

作者： LI Wei ZENG Yong-dong Key Laboratory of E ＆M Zhejiang University of Technology Ministry of Education Hangzhon 310014P. R. China

Based on the analysis of the mechanism of wire tension control by using torque motors in the multi-wire saw machining process, some mathematical models of a tension control system are studied, and an adaptive algo- rithm is designed for controlling the wire tension. In this algorithm of tension control, the rotation speeds and waving angle of motors are measured and fed back to the controller, and the NLMS（ normalized least mean squares） algorithm is used to calculate the adaptive correction value and control the wire tension accurately. The computer simulation results in Matlab software validate the high accuracy for controlling the system of the wire tension with the NLMS algorithm in the multi-wire saw machining process.

关键词： multi-wire saw wire tension adaptive control computer simulation

Mathematical Model of Heat Treatment and Its computer simulation

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Engineering Sciences 2004年第2期 15-20页

作者： Pan Jiansheng 1, Zhang Weimin 1, Tian Dong 2, Gu Jianfeng 1, Hu Mingjuan 1 (1. Shanghai Jiaotong University, Shanghai 200030 2. Shanghai Volkswagen Automotive Company Ltd., Shanghai 201805)

computer simulation on heat treatment is the foundation of intelligent heat treatment. The simulations of temperature field, phase transformation, stress/strain complicate quenching operation were realized by using the model of three dimensional non linear finite element method and the treatment methods of abruptly changing interface conditions. The simulation results basically fit those measured in experiments. The intelligent sealed multipurpose furnace production line has been developed based on the combination of computer simulation on gaseous carburizing and computer control technology. More than 3000 batches of workpieces have been processed on this production line, and all are up to standard. The application of computer simulation technology can significantly improve the loading ability and relia bility of nitriding and carburizing workpieces, reduce heat treatment distortion, and shorten carburizing duration. It is recommended that the reliable product design without redundancy should be performed with the combination of the CAD of mechanical products, the CAE of materials selection and heat treatment, and the dynamic evaluation technology of product reliability.

关键词： heat treatment mathematical model computer simulation intellectualization