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⊙第21篇⊙

分片實驗與有限元法
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注意:本論文已在《應用力學學報雜志(2000,17(2):24-30)發表
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田中旭
(大連理工大學工程力學系,116024)

摘要:本文提出分片試驗在有限元法中有著重要的作用,它是近代有限元發展的一個主要特色。得出分片試驗對位移函數和應變函數的要求,這些要求便是一個好的有限元法所應保證的;分析了幾何方程弱形式與分片試驗的關系,借此分析了雜交元、擬協調元如何滿足這些要求,以及在滿足這些要求的同時產生的對其他條件的影響;分析了精化直接剛度法、廣義協調元和雙參數法如何保證分片試驗的滿足;最后作為位移條件的應用例子,改進了BCIZ元。 
關鍵詞:分片試驗,弱形式,網線函數,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⊙

薄板彎曲問題的一種弱形式離散算子解法
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注意:本論文已在《計算力學學報》雜志(2000,17(2):163-169)發表
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田中旭 唐立民
(大連理工大學 力學系) 

摘要:本文得出了薄板彎曲問題控制微分方程弱形式,弱形式中已含邊界參數,由這個方程可以方便地得出薄板彎曲問題的數值求解格式和邊界條件的處理方法,有限元法只是它的一個特殊情況。本文導出一種離散格式,它對不再要求連續的位移函數能夠給出較高的計算精度。
關鍵詞:弱形式 邊界條件 離散算子 有限元法
分類號: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的計算機輔助機械創新設計系統研究
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注意:本論文已在《現代制造工程(原《機械工藝師》)》雜志(2001,12:11-13)發表
使用者請注明論文出處
孫延明 賴朝安 鄭時雄(華南理工大學 機電工程系 廣州 510640)

摘要:本文總結了創新設計思維的兩項原則:最短路徑原則與相似性聯想原則。分析了基于實例推理技術當前研究的不足并提出用遺傳算法進行組合優化來解決。介紹了基于WEB的創新設計知識庫,提出了功能要求、作用原理及物理結構的相似性的量化方法,用相似度作為計算機輔助聯想及遺傳算法初始群體篩選的依據,形成一種改進的遺傳算法。基于上述理論開發了基于WEB的機械產品計算機輔助創新設計系統。 
關鍵詞:機械設計;創新設計;創新思維;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⊙

面向現代制造領域的決策支持系統研究
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注意:本論文已在《現代制造工程(原《機械工藝師》)》雜志(2001,11:16-18)發表
使用者請注明論文出處

俞國燕 1 賴朝安2 鄭時雄2  孫延明
1
湛江海洋大學工程學院,廣東 湛江 524025
 2
華南理工大學機電系,廣東 廣州 510641  

 摘 要:在對當前DSS發展概述的基礎上,本文根據現代制造模式的特點,研究了面向現代制造領域的DSS應具備的協調機制、功能、結構、系統層次與實現方式,最后展望了其發展方向。 
關鍵詞: DSS; 智能化;知識獲取

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⊙

彎曲與分叉渠道潰壩波運動特性的數值預報
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注意:本論文已在《《水動力學研究與進展》雜志(Ser. A., 2002,17(1): 69-76)發表
使用者請注明論文出處

王嘉松1 , 何友聲2 , 倪漢根
1.上海交通大學機械與動力工程學院,上海200030
2. 上海交通大學工程力學系, 上海200030 3.大連理工大學土木系,大連116023

摘 要 基于TVD格式的有限差分算法思想,考慮節點與單元的對應關系,對任意四邊形單元各邊的通量采用優選限量函數的組合型TVD格式進行插值,在時間上采用兩步Runge-Kutta法離散,建立了守恒型淺水方程有限體積的高分辨率計算模型。首次針對180°強彎曲河道、90°雙支以及45°三支分叉渠道,數值預報了潰壩波的演進過程,揭示了潰壩波在彎曲河道中內外兩岸速度與水位變化,在分叉河道中自動進行流量與動量再分配,在叉點角區形成旋渦、壅高等復雜運動特征,同時反映了濕底與干底的影響。
關鍵詞 淺水方程,有限體積,TVD格式,彎曲渠道,分叉渠道,潰壩波
中圖分類號: TV131.4 文獻標識碼: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:本論文已在Journal of Hydrodynamics, Ser. B., 2000(1): 35-41發表
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EI village已經收錄本文)

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
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注意:本論文已在Journal of Hydraulic Engineering, ASCE, 2000, 126(4), 253-262發表
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.

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⊙

柔性機械臂逆動力學問題的分析和求解
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注意:本論文已在《上海交通大學學報》2002, 36(3):416-419 發表
使用者請注明論文出處

田中旭1 劉正興2 陸佑方3
(1
.上海大學,CIMS及機器人中心,上海,2000722.上海交通大學大學工程力學系,上海,200030
3.吉林大學,理學院,長春,130025

摘要:采用割線坐標系對機械臂的運動進行了描述,并分快變(振動)和慢變兩方面進行逆動力學問題的分析與求解。在對快變部分逆動力學性質的分析中發現,快變部分精確的逆動力學解是發散的。在進行柔性機械臂逆動力學求解時,應在慢變的意義上進行。文中給出了一種去掉系統快變部分的簡單方法,并進行了逆動力學求解。數值仿真結果表明,該處理方法是合理的。
關鍵詞:柔性機械臂;動力學;逆動力學;振動;大范圍運動
中圖分類號:O313.7 文獻標識碼: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⊙

巷道圍巖初始應力場和彈性模量的區間反演方法
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注意:本論文已在《巖石力學與工程學報》 2002,21(3)305-309發表
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王登剛1,2,劉迎曦1,2,李守巨1,2,剛憲約1,2

1  大連理工大學工程力學系  大連 116024;

2  工業裝備結構分析國家重點實驗室 大連 116024)

  從有限元數值計算的角度對巖土工程參數的可辨識性進行了分析。在可辨識性分析的基礎上,考慮觀測數據的不確定性,引入不確定問題求解的區間分析思想,建立了聯合采用圍巖位移和應力觀測數據同時識別地應力和圍巖彈性模量的反演模型。并采用約束變尺度方法求解該反演模型,獲得地應力和彈性模量所在區間范圍。
關鍵詞
區間分析,約束變尺度方法,初始應力場,彈性模量
中圖分類號
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⊙

非線性最優化問題的一種混合解法
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注意:本論文已在《工程力學 》2001,18(3)61-66發表
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(EI已收錄本文)

王登剛1,2 ,劉迎曦1,2 ,李守巨1,2

(1.大連理工大學工程力學系,遼寧 大連,116023;2.工業裝備結構分析國家重點實驗室,遼寧大連,116023)

摘 要:把BFGS方法與混沌優化方法相結合,基于混沌變量提出一種求解具有變量邊界約束非線性最優化問題的混合優化方法。混合算法兼顧了混沌優化全局搜索能力強和BFGS方法收斂速度快的優點,成為一種求解非凸優化問題全局最優的有效方法。算例表明,當混沌搜索的次數達到一定數量時,混合優化方法可以保證算法收斂到全局最優解,且計算效率比混沌優化方法有很大提高。
關鍵詞:混合法;BFGS方法;混沌優化方法;全局最優
中圖分類號:O39 文獻標識碼: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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