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一维二维扩散模型Matlab代码
该程序采用有限差分方法(隐式和显式)仿真了一维和二维域扩散方程。
- 2020-12-06下载
- 积分:1
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太阳能控制系统源代码
【实例简介】太阳能控制系统源代码共赏,是用C语言开发的,请参考。
- 2021-11-11 00:34:55下载
- 积分:1
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Tebo-ICT(腾博)
ICT ATE FCT测试必备强软,懂的进
- 2020-11-02下载
- 积分:1
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TSP 蚁群算法 MFC实现
对旅行商问题的解法提出了蚁群算法,并用MFC编程实现,有比较有好的界面,并对问题做了细致的分析。
- 2020-11-29下载
- 积分:1
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Coursera课程Deeplearning深度学习笔记+课后编程作业源码
这是Coursesra深度学习课程全部的中文翻译版本,对于时间不宽裕或者习惯阅读文献的同学学习深度学习十分有利,也能解决了视频在线课程也有其弊端,就跟很多人不喜欢微信语音一样,想要在视频中查找和回顾相关的知识点并不方便。课后编程作业代码已更新到最后一周,感谢黄海广博士等最资源的整理。
- 2020-12-12下载
- 积分:1
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加速遗传算法
自己写的一个加速遗传算法的MATLAB的程序
- 2020-11-27下载
- 积分:1
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基于ABAQUS的高速切削切屑形成过程的有限元模拟
基于有限元分析软件ABAQUS的Johnson-Cook材料模型以及断裂准则模拟高速切削淬硬钢锯齿状切屑形态,并讨论刀具前角和锯齿状切屑形态对切削力的影响。研究表明仿真结果和试验结果是一致的,文中介绍的有限元模拟方法可以准确地模拟并预测高速切削淬硬钢时的切屑形成过程。刀4有限元模拟及试验结果将有限元模拟仿真预测的切屑形态与试验结果进行比较,如图2、图3、图4所示。预测的切屑形态结果以积分点处等效塑性应变( equivalent plastic strain,PEEQ)的形式显示。由图中可以看出,有限元预测的切屑形态与试验结果非常接近。图中PEEQ的最大值随刀具前角从-10°改变到10而逐渐减小,说明主剪切(a)锯齿状切屑显微照片(b)锯齿状切屑形态有限元模拟结果区内的切屑变形也随刀具前角的增大而减小。刀具前(a) A micrograph of(b) fe simulation result of serrated角对切屑形态有重要影响,当使用负前角时容易形成serrated chipchip morphology锯齿状切屑。图4锯齿状切屑形态有限元模拟仿真与试验结果的对比(Fig 4 Comparison between experimentally and numerically obtained80.70.6hI号0.5H总0.4(a)锯齿状切屑显微照片(b)锯齿状切屑形态有限元模拟结果(a)a micrograph of(b)fe simulation result of serrated肥0.2●试验结果 Experimental resulserrated chipch0:→摸拟结果 Simulation result图2锯齿状切屑形态有限元模拟仿真与试验结果的对比(yo=-10)1010Fig 2 Comparison between experimentally and numerically obtained刀具前角 Tool rake angle(°)chip morphology (Yo =-10)图5不同刀具前角条件下的锯齿化程度Fig 5 Sawtooth degree under different tool rake angles4000003600320.l6000012000(a)锯齿状切屑显微照片(b)锯齿状切屑形态有限元模拟结果4000(a)A microgram(b)FE simulation result of serrated0.000.050.100.150.20serrated chchip morphology时间Time×103/s图3锯齿状切屑形态有限元模拟仿真与图6锯齿状切屑形成时的切削力波动(y6=-10)试验结果的对比(y0=0)Fig 6 Efect of tool angle on the cutting force(%o =-10Fig 3 Comparison between experimentally and numerically obtained加而逐渐降低。刀具前角对切削力也有很大影响,如图6、图7和图8所示,平均切削力F的值随着刀具刀前通常使用锯齿化程度C9表示锯齿状切屑变形和角的增加而逐渐降低。切屑形态。Gs的定义如下Gs =(H-h,)/h(4)5结论Gs的测量方法如图2所示,Gs与刀具前角之间的关系本文的目的在于预测高速切削过程中的切屑形如图5图5说明模拟结果与试验结果符合很好,当切态。使用适合高速变形条件的 Johnson-Cook材料模削速度和进给量一定时,锯齿化程度随刀具前角的增型、断裂准则和 ABAQUS有限元软件,模拟并测量高速0.80LIU Zhan Qiang, WAN Yi, AI Xing. Cutting forces in High Speed Milling[J]. China Mechanical Engineering, 2003, 14(9): 734-737( In Chix0.60[2]Kishawy H A. An experimental evaluation of cutting temperature duringhigh speed machining of hardened D2 tool steel[ J]. Machining Science0.40and Technology, 2002, 6(1): 67-79[3]刘战强,艾兴.高速切削刀具磨损表面形态研究[门摩擦学学〓0.20报,2002,22(6):468-471RLIU Zhan Qiang, Al Xing. Wear characteristics of cutting tools in high尽0speed machining[J]. Tribology, 2002, 22(6): 468-471( In Chinese)0.000.050.100.150.20[4]赵文祥,龙震海,王西彬,等.高速切削超高强度钢时次表面层时间 Time x103/s的组织特性研究[J.航空材料学报,200,25(4):2025图7锯齿状切屑形成时的切削力波动(y0=0)ZHAO Wen Xiang, LONG ZhenHai, WANG XiBin, et al. Study on theFig7 Effect of tool angle on the cutting force(yo =00)metallurgical structure characters of sub-surface layer of ultra-high strength0.80alloy steel in high speed milling condition[J]. Joumal of Aeronautical MEterials, 2005, 25(4): 20-25( In Chinese)[5] Sung H R, Soo-Ik 0. Prediction of serrated chip formation in metal cutting0.60process with new flow stress model for AISI 1045 steellJ]. Joumal of Ma-terials Processing Technology, 2006,171: 417-4220.40[6】赵军,孟辉,王素玉,等.高速切削锯齿状切屑的有限元模拟[.工具技术,2005,39(1):29-310.20ZHAO Jun, MENG Hui, WANG SuYu, et al. Finite element simulatinganalysis of serrated chip formation in high speed cutting[J]. Tool Engi-0ing,2005,39(1):29-31( In Chinese)早0.000050.100.150.20时间 Time x103/s[7]Christian H, Svendsen B. Simmlation of chip formation during high-speed图8锯齿状切屑形成时的切削力波动(=10)cutting[ J]. Joumal of Materials Processing Technology, 2007, 186: 66Fig8 Effect of tool angle on the cutting force(%o = 100)[8] Klocke F, Raedt H W, Hoppe S. 2D-deform simulation of the orthogonal切削AISI4340钢过程中不同刀具前角条件下的切屑high speed cutting process[]. Machining Science and Technology, 2001形态和切削力,讨论刀具前角和切屑形态对切削力的5(3):323-340.影响。研究结果表明,模拟结果与试验结果能很好地9)]shkH,AbeE, Sahm a. Material aspects of chip formation in HSC相符。因此,本文使用的有限元模拟方法可以准确预machining[ J]. Amals of the CIRP- Manufacturing Technology, 2001, 50(1)测高速切削淬硬钢时切屑形成过程。参考文献( References)[1]刘战强,万熠,艾兴.高速铣削中切削力的研究[J.中国机械工程,2003,14(9):734-737.
- 2020-12-07下载
- 积分:1
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eeglab教程
eeglab教程,有详细的操作说明。帮助你处理脑电。
- 2020-12-10下载
- 积分:1
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360环视摄像头鱼眼四摄像头拼接算法
用于鱼眼摄像头的一个环视参考文档很不错,自己最开始做这个相关的项目就是参考这个文档,发现写的很是不错,非常值得参考特别有用的,哈哈哈哈哈哈哈哈哈哈赵三峰,谢明,陈玉明:基于逆向投影的全景泊车系统设计与实现其中,(x,y)表示校正图像的坐标,(x,y)表示鱼眼图像的坐标此算法的效果如图所示。1------图校正前后图像俯视变换clay.OB图离散化后的路面本文采用直接线性变换()来找到俯视变换的投影矩阵,这种方法的优点在于不需要知道摄像头视RR角等参数,只需要在图像坐标系下标定对特征点就可R以计算出个未知的参数,从而得到单应性矩阵,并利R用单应性矩阼完成俯视变换。其中,M表示合成图像的宽度,单位:像素;No表示直接线性变换的公式如下合成图像的高度,单位:像素;R表示合成区域的宽Coxi i+Coli+Cu22i +Cu3)度,单位:;R1表示合成区域的长度,单位(iam,0)表示图像的坐标,单位:像素;x,y表示合成区C102+(ny2+C12x;+CrC20x:+C21y+C2231+1)域路面的坐标,单位:。下面判断路面上的点被哪个摄像头拍到,因此将路其中,(2v)表示图像坐标,(xy2)为物体空间坐标,面分成八个区域,如图所示Co,co1,…,C2为未知参数。但是本文的物体选择的是路面特征点,因此公式的z=0,简化后的二维公式为:(左前前)(右前)IX). Ti t Coli+CUsC0x;+C21y;+1(左)汽车v C1o x, +C11)2+C13C20x:+C21y1+1如果川矩阵的形式表示,如下(左后)(后)(右后)ROT=C1C1 CI图路而的八个区域图中,Il、ⅣV、V和ⅤI四个区域只能被前,左,RO表示路面坐标到图像左边的变换矩阵,则ROn右,后四个摄像头看到。I、I、VI和VI为两个摄像表示图像到路面的投影矩阵头的交叉区域,可能被两个摄像头看到,因此需要判断图像合成交叉区域被哪个摄像头采集到,四个交叉区域的判别方本文的创新点就在于跳出了传统图像拼接的想维,法相同,因此以区域1为例描述如下采用一种更加简单有效的算法来实现无缝拼接全景。)取区域I内任意一点(jo),计算其路面坐标假设路面合成区域的大小为长R1,宽为Rw,单假定该点可以被前摄像头采集到,通过与前摄位:。R的宽度方向平均分成M等份,R1的高像头的投影矩阵ROlo相乘,便可以得到该点在前摄度方向平均分成N等份,其中任意一点坐标用(mm)像头的像素坐标av),如果0≤
- 2020-11-28下载
- 积分:1
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MSC.Marc 2013.1理论手册
MSC.MARC是功能齐全的高级非线性有限元软件,具有极强的结构分析能力。可以处理各种线性和非线性结构分析包括:线性/非线性静力分析、模态分析、简谐响应分析、频谱分析、随机振动分析、动力响应分析、自动的静/动力接触、屈曲/失稳、失效和破坏分析等ContentsMarc Volume A: Theory and User InformationrefaceAbout this manual■■■■20Purpose of volume A20Contents of volume a20How to Use this manual211 The Marc SystemMarc Programs............■■23Marc for Analysis23Mentat or patran for gul24Structure of marc24Procedure Library24Material Library24Element Library25Program Function Library25Features and benefits of marc252 Program InitiationMarc Host Systems27Workspace Requirements27Marc Workspace Requirements27File Units30Program Initiation.........32Examples of running marc Jobs■■■■■344 Marc Volume A: Theory and User Information3 Data EntryInput Conventions38Input of List of Items39Examples of lists41Table Driven Input■■41Table Input42Parameters46Model Definition Options46History Definition Options46REZONE Option474 Introduction to mesh definitionDirect Input49Element Connectivity Data49Nodal coordinate data53Activate/Deactivate54User Subroutine Input54MESH2D54Block definition54Merging of Nodes54Block Types55Symmetry, Weighting, and Constraints57Additional Options58Mentat58FXORD Option59Major classes of the fXoRD Option59Recommendations on Use of the FXORD Option63Incremental mesh generators■■■■■63Bandwidth Optimization64Rezoning.....64Substructure65Technical Background66Scaling Element Stiffness67Contents 5BEAM SECT Parameter■■■68Orientation of the Section in Space68Definition of the section68Error Analysis74ocal AdaptivityNumber of Elements Created7474Boundary Conditions75Location of new nodes76Adaptive Criteria77Automatic Global remeshing80Remeshing criteria84Remeshing TechniquesPatran Tetrahedral mesher885 Structural Procedure LibraryLinear Analysis99Accuracy100Error estimates100Adaptive meshing101Fourier Analysis101Nonlinear Analysis104Geometric nonlinearities108Eulerian FormulationArbitrary Eulerian-Lagrangian(AEL) Formulation118Nonlinear Boundary Conditions118Buckling Analysis120Perturbation Analysis121Computational Procedures for Elastic-Plastic Analysis126Creep138Viscoelasticity142Viscoplasticity143Fracture Mechanics144Linear fracture mechanics144Nonlinear fracture mechanics147Numerical Evaluation of the J-integral148Numerical Evaluation of the Energy Release Rate with the VCCT Method150Automatic Crack PropagationDynamic Fracture Methodology1626 Marc Volume A: Theory and User InformationDynamic crack Propagation..162Crack Initiation163Mesh Splitting165Mesh Splitting Along Edges or Faces165Mesh Cutting167Dynamics...168Modal(Eigenvalue) Analysis.168Harmonic Response172Spectrum Response75Transient Analysis179Inertia relief191Rigid Body Mode Evaluation.191Rigid-Plastic Flow195Steady State Analysis95Transient Analysis196Technical background..196Superplasticity197Soil Analysis199Technical formulation200Mechanical Wear.,,,,,,,,203Design Sensitivity Analysis........■■205Theoretical considerations207Design Optimization208Approximation of Response Functions Over the Design Space..209Improvement of the Approximation211The Optimization algorithmMarc User Interface for Sensitivity Analysis and Optimization212Define Initial State with Results from a Previous Analysis215Pre state215Model sections217Steady State Rolling Analysis219Kinematics219lnetⅰaE仟fect...221Rolling Contact221Steady state rolling with marc221ContentsStructural Zooming Analysis.222Element Types Supported223Uncoupled Thermal Stress Analysis223Cure-Thermal-Mechanically Coupled Analysis224Cure Kinetics225Cure Shrinkage Strain228References,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,2296 Nonstructural Procedure LibraryHeat Transfer234Thermal Contact235Convergence Controls235Steady state Analysis236Transient Analysisemperature Effects238Initial Conditions239Boundary Conditions239Surface Energy243Thermochemical Ablation and Surface Energy Balance244Mathematical Presentation244Mechanical Erosion251Mechanical Erosion by Other Actions251pyrolySis251Coking255Monitoring Thermal Degradation258Presentation of the Energy Equation260Ablation262Welding27Radiation278Conrad Gap292Channel293Output294Diffusion295Technical Background296Hydrodynamic Bearing300Technical Background3028 Marc Volume A: Theory and User InformationElectrostatic Analysis304Technical Background305Magnetostatic Analysis308Technical background..309Magnetodynamic Analysis∴∴320Technical Background322Piezoelectric Analysis325Technical Background326Strain Based Piezoelectric Coupling..328Acoustic Analysis328Rigid Cavity Acoustic Analysis328Technical Background329Fluid mechanics330Finite element formulation333Penalty Method335Steady State Analysis336Transient Analysis336Solid Analysis336Solution of Coupled Problems in Fluids..336Degrees of Freedom337Element Types.337Coupled Analyses∴..■量■画■■■,,,,,,,,339Thermal Mechanically Coupled Analysis341Coupled Acoustic-Structural AnalysisFluid/Solid Interaction- Added Mass Approach342346Coupled Electrostatic-Structural Analysis348Coupled Magnetostatic-Structural Analysis350Coupled Thermal-Electrical Analysis (Joule Heating)352Coupled Electrical-Thermal-Mechanical Analysis355Coupled Magnetostatic-Thermal Analysis357Coupled Magnetodynamic-Thermal Analysis358Coupled Magnetodynamic-Thermal-Structural Analysis..359References∴,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,362Contents 97 Material LibraryLinear Elastic Material365Composite Material ......367Layered Materials368Classical Lamination Theory for Multi-Layered Shells371Material Preferred direction372Material Dependent Failure Criteria376Interlaminar Shear for Thick Shell, Beam, Solid shell, and 3-d Composite brick elements394Interlaminar Stresses for continuum composite elements397Progressive Composite Failure397Mixture model399Gasket403Constitutive model403Nonlinear Hypoelastic Material407Thermo-Mechanical Shape Memory Model422Transformation Induced deformation424Constitutive Theory425Phase Transformation strains425Experimental Data Fitting for Thermo-mechanical Shape Memory Alloy427Mechanical Shape Memory Model431Conversion from Thermo-Mechanical to Mechanical SMA oyExperimental Data Fitting for Mechanical Shape Memory alle434435Elastomer436Updated Lagrange formulation for nonlinear elasticity455Time-independent Inelastic Behavior456Yield Conditions458Mohr-Coulomb Material(Hydrostatic Stress Dependence)464Buyukozturk Criterion(Hydrostatic Stress Dependence)465Powder material465Obtaining Crush Curve and Shear Failure Parameters by Curve Fitting in Marc475Work or strain hardening.....,,,479Flow rule485Constitutive Relations486Time-independent Cyclic Plasticity489Time-dependent Inelastic Behavior492Creep(Maxwell Model)翻495Oak Ridge National Laboratory Laws50010 Marc Volume A: Theory and User InformationSwelling.501Viscoplasticity502Time-dependent Cyclic Plasticity502Anand solder model504Viscoelastic Material505Bergstrom-Boyce Model516Narayanaswamy Model518Frequency-dependent Material Behavior522Viscoelastic Material Behavior in the Frequency Domain522Thermo-Rheologically Simple Material Behavior in the Frequency Domain538Deformation Dependent Relaxation in the Frequency Domain539Harmonic Equations of motion541Performing viscoelastic Analysis in the Frequency Domain543Temperature Effects and Coefficient of Thermal Expansion,546Piecewise Linear Representation547Temperature-Dependent Creep548Coefficient of Thermal Expansion549Time-Temperature-Transformation549Low Tension Material552Uniaxial Cracking Data552LoW Tension Cracking552Tension Softening552Crack Closure553Crushing553Analysis554Soil model554Elastic Models554Cam-Clay Model555Evaluation of soil parameters for the critical state soil model557Damage Models565Ductile metals565Elastomers568Cohesive Zone Modeling570Nonstructural materials578Heat transfer analysis579Piezoelectric Analysis579Thermo-Electrical Analysis579Coupled Electrical-Thermal-Mechanical Analysis579Hydrodynamic Bearing AnalysisFluid/ Solid Interaction Analysis- Added Mass approach579.579
- 2020-12-04下载
- 积分:1