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⊙第21篇⊙

分片实验与有限元法
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注意:本论文已在《应用力学学报杂志(2000,17(2):24-30)发表
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田中旭
(大连理工大学工程力学系,116024)

摘要:本文提出分片试验在有限元法中有着重要的作用,它是近代有限元发展的一个主要特色。得出分片试验对位移函数和应变函数的要求,这些要求便是一个好的有限元法所应保证的;分析了几何方程弱形式与分片试验的关系,借此分析了杂交元、拟协调元如何满足这些要求,以及在满足这些要求的同时产生的对其他条件的影响;分析了精化直接刚度法、广义协调元和双参数法如何保证分片试验的满足;最后作为位移条件的应用例子,改进了BCIZ元。 
关键词:分片试验,弱形式,网线函数,有限元法

Patch Test and Finite Element Method

Tian Zhongxu
(Dalian University of technology, 116024)

Abstract: This paper realized that the Patch Test is very important to Finite Element Methods. Derive the requirement to strain and displacement of Patch Test. Give the relationship between weak form of continuity equation and the Patch Test, through which the hybrid element method and quasi-conform element method are analyzed. Refined direct stiffness method and generalized conforming elements are also analyzed about why they can pass patch test. At last, as an example of using the requirement of patch test for displacement, improved the BCIZ Element.

Key Words: patch test, weak form, string-net function, finite element method


⊙第22篇⊙

薄板弯曲问题的一种弱形式离散算子解法
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注意:本论文已在《计算力学学报》杂志(2000,17(2):163-169)发表
使用者请注明论文出处

田中旭 唐立民
(大连理工大学 力学系) 

摘要:本文得出了薄板弯曲问题控制微分方程弱形式,弱形式中已含边界参数,由这个方程可以方便地得出薄板弯曲问题的数值求解格式和边界条件的处理方法,有限元法只是它的一个特殊情况。本文导出一种离散格式,它对不再要求连续的位移函数能够给出较高的计算精度。
关键词:弱形式 边界条件 离散算子 有限元法
分类号:O242.21

A Weak Form Discrete Operator Method of Solving Thin Plate Bending Problems

Tian Zhongxu, Tang Limin
(Dalian University of Technology)

Abstract: The weak form formula of thin plate bending problems is presented, which includes the boundary parameters. From this formula, both the solving forms and the method of dealing with boundary conditions can be got. The finite element method is only one of these forms. A discrete form is given, which proved to be with high accuracy even when the displacement lost continuity.
Key Words: weak form; boundary condition; discrete operator; finite element method


⊙第23篇⊙

基于WEB的计算机辅助机械创新设计系统研究
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注意:本论文已在《现代制造工程(原《机械工艺师》)》杂志(2001,12:11-13)发表
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孙延明 赖朝安 郑时雄(华南理工大学 机电工程系 广州 510640)

摘要:本文总结了创新设计思维的两项原则:最短路径原则与相似性联想原则。分析了基于实例推理技术当前研究的不足并提出用遗传算法进行组合优化来解决。介绍了基于WEB的创新设计知识库,提出了功能要求、作用原理及物理结构的相似性的量化方法,用相似度作为计算机辅助联想及遗传算法初始群体筛选的依据,形成一种改进的遗传算法。基于上述理论开发了基于WEB的机械产品计算机辅助创新设计系统。 
关键词:机械设计;创新设计;创新思维;相似性

Research on application of Web-based computer-aided mechanical creative design system
SUN YanMing
LAI ChaoAn ZHENG ShiXong
(mechatronic engineering Department, south china university of technology, Guangzhou 510640)

Abstract: Two item of principle of creative design thinking were summarized in this paper: shortest route principle and similarity association principle. It analyzed the disadvantage of the current study on CBR and proposed applying GA in combination and optimize to resolve them, and introduced a kind of web-based creative design repository. It advanced a kind of measure method of similarity among function demandaction principium and substance structure using similarity degree as the bases on which computer-aided association can be realized and the original colony of GA can be selected reasonably, thus a kind of improved GA came into being. A web-based computer-aided creative design system has been developed based on above theory. 
Keywords: Mechanical design; Creative design; Creative thinking; Similarity


⊙第24篇⊙

面向现代制造领域的决策支持系统研究
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注意:本论文已在《现代制造工程(原《机械工艺师》)》杂志(2001,11:16-18)发表
使用者请注明论文出处

俞国燕 1 赖朝安2 郑时雄2  孙延明
1
湛江海洋大学工程学院,广东 湛江 524025
 2
华南理工大学机电系,广东 广州 510641  

 摘 要:在对当前DSS发展概述的基础上,本文根据现代制造模式的特点,研究了面向现代制造领域的DSS应具备的协调机制、功能、结构、系统层次与实现方式,最后展望了其发展方向。 
关键词: DSS; 智能化;知识获取

Research on the Decision Support System for Modern Manufacturing Domain
Yu Guoyan1 Lai Chaoan2 Zheng Shixiong2 Sun Yanming2 
ZhanJiang ocean university, Guangdong ZhanJiang, 524025 China1
South China University of Technology, Guangdong Guangzhou, 510640, China2

Abstract: Based on the introduction of DSS development, the paper discusses the harmonizing mechanism, function, structure, arrangement and realizing way of DSS for modern manufacturing system according to the characteristic of modern manufacturing mode. At last, the development direction is prospected.
Keywords
:DSS; Intelligent; knowledge acquisition


⊙第25篇⊙

弯曲与分叉渠道溃坝波运动特性的数值预报
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注意:本论文已在《《水动力学研究与进展》杂志(Ser. A., 2002,17(1): 69-76)发表
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王嘉松1 , 何友声2 , 倪汉根
1.上海交通大学机械与动力工程学院,上海200030
2. 上海交通大学工程力学系, 上海200030 3.大连理工大学土木系,大连116023

摘 要 基于TVD格式的有限差分算法思想,考虑节点与单元的对应关系,对任意四边形单元各边的通量采用优选限量函数的组合型TVD格式进行插值,在时间上采用两步Runge-Kutta法离散,建立了守恒型浅水方程有限体积的高分辨率计算模型。首次针对180°强弯曲河道、90°双支以及45°三支分叉渠道,数值预报了溃坝波的演进过程,揭示了溃坝波在弯曲河道中内外两岸速度与水位变化,在分叉河道中自动进行流量与动量再分配,在叉点角区形成旋涡、壅高等复杂运动特征,同时反映了湿底与干底的影响。
关键词 浅水方程,有限体积,TVD格式,弯曲渠道,分叉渠道,溃坝波
中图分类号: TV131.4 文献标识码:A

Numerical simulation of dam-break flowsin bend and furcated channels 
  Wang Jia-song1 He You-sheng1 Ni Han-gen2(1.Shanghai Jiaotong University, Shanghai 200030; 2. Dalian University of Technology, Dalian 116023)   

Abstract  A high-resolution finite-volume method for solving the conservative shallow water equations is presented in this paper. The method is based upon extending the finite-difference TVD scheme to finite-volume method considering the corresponding relationships between elements and nodes. A second-order hybrid TVD scheme with an optimum-selected limiter and a two-step Runge-Kutta method are utilized to discretize the integral type of the shallow water equations over arbitrary quadrilateral cells. The dam-break flows are simulated for the first time considering the cases in channels with a 180°strong bend, a 90°bifurcation and a 45°three branches. The complex characteristics of velocity and water elevation changes at both banks of the curved sections, auto-reassignment of discharges and momentum as well as vortices and super-elevation near the corner of embranchment regions in the furcated channels are displayed. The effects of wetting bed and drying bed are discussed simultaneously.  Key words shallow water equations, finite-volume method, bend channel, furcated channel, dam-break  Bores 


⊙第26篇⊙

A HIGH RESOLUTION FINITE VOLUME METHOD FOR SOLVING SHALLOW WATER EQUATIONS
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注意:本论文已在Journal of Hydrodynamics, Ser. B., 2000(1): 35-41发表
使用者请注明论文出处

EI village已经收录本文)

Wang Jia-song (王嘉松)
School of Civil Engineering and Mechanics, Shanghai JiaoTong University, Shanghai 200030, P. R. China 
Ni Han-gen
School of Civil and Structure Engineering, Dalian University of Technology, Dalian 116024, P. R. China

ABSTRACT: A high-resolution finite volume numerical method for solving the shallow water equations is developed in this paper. In order to extend finite difference TVD scheme to finite volume method, a new geometry and topology of control bodies is defined considering the corresponding the relationships between nodes and elements. This solver is implemented on arbitrary quadrilateral meshes and their satellite elements, and based on a second-order hybrid type TVD scheme in space discretization and a two-step Runge-Kutta method in time discretization. Then it is used to deal with two typical dam-break problems and very satisfactory results are obtained comparing with other numerical solutions. It can be considered as an efficient implement for the computation of shallow water problems, especially concerning those having discontinuities, subcritical and supercritical flows and with complex geometries.
KEY WORDS: shallow water equations, finite volume, TVD scheme, dam-break bores


⊙第27篇⊙

Finite-Difference TVD Scheme for Computation of Dam-Break Problems
下载英语论文全文请点击上面的链接
注意:本论文已在Journal of Hydraulic Engineering, ASCE, 2000, 126(4), 253-262发表
使用者请注明论文出处
.

By J. S. Wang 1(王嘉松) , H. G. Ni 2 and Y. S. He 3

1 Post-Doctoral Fellow, School of Civ. Engrg. and Mech., Shanghai Jiao Tong Univ., Shanghai 200030, P.R.China.
2 Prof., Dept. of Civ. Engrg., Dalian Univ. of Tech., Dalian 116024, P.R.China.
3 Prof., School of Civ. Engrg. and Mech., Shanghai Jiao Tong Univ., Shanghai 200030, P.R.China.

ABSTRACT: A second-order hybrid type of total variation diminishing (TVD) finite-difference scheme is investigated for solving dam-break problems. The scheme is based upon the first-order upwind scheme and the second-order Lax-Wendroff scheme, together with the one-parameter limiter or two-parameter limiter. A comparative study of the scheme with different limiters applied to the Saint Venant equations for 1D dam-break waves in wet bed and dry bed cases shows some differences in numerical performance. An optimum-selected limiter is obtained. The present scheme is extended to 2D shallow water equations by using an operator-splitting technique, which is validated by comparing the present results with the published results, and good agreement is achieved in the case of a partial dam-break simulation. Predictions of complex dam-break bores, including the reflection and interactions for 1D problems and the diffraction with a rectangular cylinder barrier for a 2D problem, are further implemented. The effects of bed slope, bottom friction, and depth ratio of tailwater/reservoir are discussed simultaneously.
Key words: Saint Venant equations, shallow water equations, TVD, finite-difference, dam-break waves, reflection, diffraction, one-parameter limiter, two-parameter limiter


⊙第28篇⊙

柔性机械臂逆动力学问题的分析和求解
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注意:本论文已在《上海交通大学学报》2002, 36(3):416-419 发表
使用者请注明论文出处

田中旭1 刘正兴2 陆佑方3
(1
.上海大学,CIMS及机器人中心,上海,2000722.上海交通大学大学工程力学系,上海,200030
3.吉林大学,理学院,长春,130025

摘要:采用割线坐标系对机械臂的运动进行了描述,并分快变(振动)和慢变两方面进行逆动力学问题的分析与求解。在对快变部分逆动力学性质的分析中发现,快变部分精确的逆动力学解是发散的。在进行柔性机械臂逆动力学求解时,应在慢变的意义上进行。文中给出了一种去掉系统快变部分的简单方法,并进行了逆动力学求解。数值仿真结果表明,该处理方法是合理的。
关键词:柔性机械臂;动力学;逆动力学;振动;大范围运动
中图分类号:O313.7 文献标识码:A

the Analysis and Solution for Inverse Dynamic Problems of Flexible Arms 

Tian Zhongxu1 Liu Zhengxing2 Lu Youfang3
1Center of CIMS & robotics, Shanghai University, 200072; 2Department of Engineering mechanics, Shanghai Jiaotong University, 2000303Institute of Science, Jilin University 130025

AbstracetThe paper concentrates on the analysis and solution for inverse problems of flexible arms. The secant coordinate system is introduced to describe the location of the two-link arm. The fast (vibration) part and the slow part are analyzed for the inverse problems. The solutions for the fast part are found emanative through the analysis. So, the solution for the flexible arms should be carried out while only the slow part is included. A sample method is given to get rid of the fast part and get the solutions for the inverse problems. Numerical results show that this method is correct.
Key words:flexible arm;dynamic;inverse dynamic;vibration;movement with large range


⊙第29篇⊙

巷道围岩初始应力场和弹性模量的区间反演方法
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注意:本论文已在《岩石力学与工程学报》 2002,21(3)305-309发表
使用者请注明论文出处

王登刚1,2,刘迎曦1,2,李守巨1,2,刚宪约1,2

1  大连理工大学工程力学系  大连 116024;

2  工业装备结构分析国家重点实验室 大连 116024)

  从有限元数值计算的角度对岩土工程参数的可辨识性进行了分析。在可辨识性分析的基础上,考虑观测数据的不确定性,引入不确定问题求解的区间分析思想,建立了联合采用围岩位移和应力观测数据同时识别地应力和围岩弹性模量的反演模型。并采用约束变尺度方法求解该反演模型,获得地应力和弹性模量所在区间范围。
关键词
区间分析,约束变尺度方法,初始应力场,弹性模量
中图分类号
O39TU457

Interval back analysis for the initial stresses and elastic modulus of the surrounding rock of tunnels

WANG Denggang1,2, LIU Yingxi1,2, LI Shouju1,2  and GANG Xianyue1,2

 (1  Dept. of Eng. Mechanics., Dalian Univ. of Technol. Dalian, 116024, China)

(2    State Key Lab. of Struct. Anal. of Ind. Equip., Dalian, 116024, China)

Abstract  The differentiability of the initial stresses and elastic constants of the surrounding rock of tunnels was discussed firstly from the view of finite element method. An interval back analysis model was put forward to identify these parameters based on the measured data of deformation and disturbed stress in the surrounding rock. The uncertain property of the measured data was considered and the interval analysis method to solve the uncertain problems was induced in the present model. The interval of the initial stresses and elastic modulus can be obtained by using the constrained variable metric method to solve the present model.

Key words  interval analysis, constrained variable metric method, initial stress field, elastic modulus 


⊙第30篇⊙

非线性最优化问题的一种混合解法
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注意:本论文已在《工程力学 》2001,18(3)61-66发表
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(EI已收录本文)

王登刚1,2 ,刘迎曦1,2 ,李守巨1,2

(1.大连理工大学工程力学系,辽宁 大连,116023;2.工业装备结构分析国家重点实验室,辽宁大连,116023)

摘 要:把BFGS方法与混沌优化方法相结合,基于混沌变量提出一种求解具有变量边界约束非线性最优化问题的混合优化方法。混合算法兼顾了混沌优化全局搜索能力强和BFGS方法收敛速度快的优点,成为一种求解非凸优化问题全局最优的有效方法。算例表明,当混沌搜索的次数达到一定数量时,混合优化方法可以保证算法收敛到全局最优解,且计算效率比混沌优化方法有很大提高。
关键词:混合法;BFGS方法;混沌优化方法;全局最优
中图分类号:O39 文献标识码:A

A Hybrid Approach for Nonlinear Optimization

WANG Denggang1,2 ,  LIU Yingxi1,2 ,  LI-Shouju1,2

(1. Dalian University of Technology, Dalian, 116023     2.State Key Lab. of Struct. Anal. of Ind. Equip., Dalian, 116023) 

AbstractCombined BFGS method with chaos optimization method, a hybrid approach was proposed to solve nonlinear optimization problems with boundary restraints of variables. The hybrid method is an effective approach to solve nonconvex optimization problems, as it given both attentions to the inherent virtue to locate global optimum of chaos optimization method and the advantage of high convergence speed of BFGS method. Numerical examples illustrate that the present method possesses both good capability to search global optima and far higher convergence speed than that of chaos optimization method.
key words
hybrid approachBFGS methodchaos optimization methodglobal optimum


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