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Effects of viscosity on shock-induced damping of an initial sinusoidal disturbance

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Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 802-806页

作者： MA XiaoJuan1,LIU FuSheng1 & JING FuQian2 1 College of Physical Science and Technology,southwest jiaotong university,chengdu 610031,china 2 Laboratory for Shock Wave and Detonation Physics Research,Institute of Fluid Physics,Chinese Academy of engineering Physics,Mianyang 621900,china 1. College of Physical Science and Technology Southwest Jiaotong University Chengdu 610031 China2. Laboratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics Chinese Academy of Engineering Physics Mianyang 621900 China

A lack of reliable data treatment method has been for several decades the bottleneck of viscosity measurement by disturbance amplitude damping method of shock *** this work the finite difference method is firstly applied to obtain the numerical solutions for disturbance amplitude damping behavior of sinusoidal shock front in inviscid and viscous *** water shocked to 15 GPa is taken as an example,the main results are as follows:(1) For inviscid and lower viscous flows the numerical method gives results in good agreement with the analytic solutions under the condition of small disturbance(a0/λ=0.02);(2) For the flow of viscosity beyond 200 Pa s(η=κ) the analytic solution is found to overestimate obviously the effects of *** is attributed to the unreal pre-conditions of analytic solution by Miller and Ahrens;(3) The present numerical method provides an effective tool with more confidence to overcome the bottleneck of data treatment when the effects of higher viscosity in experiments of Sakharov and flyer impact are expected to be analyzed,because it can in principle simulate the development of shock waves in flows with larger disturbance amplitude,higher viscosity,and complicated initial flow.

关键词： viscosity coefficient two-dimensional Eulerian flow shock front sinusoidal disturbance

Stability　Criteria　for　Large－Scale　Linear　Systems　with　Structured　Uncertainties

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Journal of Modern Transportation 1996年第2期13卷 46-53页

作者： Cao Dengqing Institute of Applied Mechanics,southwest jiaotong university,chengdu 610031,china

The robust stability analysis for large scale linear systems with structured time varying uncertainties is investigated in this *** using the scalar Lyapun... 详细信息

The robust stability analysis for large scale linear systems with structured time varying uncertainties is investigated in this *** using the scalar Lyapunov functions and the properties of M matrix and nonnegative matrix,stability robustness measures are *** robust stability criteria obtained are applied to derive an algebric criterion which is expressed directly in terms of plant parameters and is shown to be less conservative than the existing ones.A numerical example is given to demonstrate the stability criteria obtained and to compare them with the previous ones.

关键词： large scale system robust stability structured uncertainty Lyapunov method decentralized control

Numerical Simulation for Prediction of Wind Loads on Building Surfaces

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Journal of Modern Transportation 1997年第1期14卷 56-62页

作者： Zhang Xiaogang Institute of Applied Mechanics, southwest jiaotong university, chengdu 610031, china

The reliability of the numerical K ε model for determining wind pressure on building surfaces is evaluated. The solution algorithm is based on a body fitted non orthogonal curvilinear coordinate system and a staggered grid arrangement. The covariant velocity components are chosen as dependent variables. Convective fluxes are described by the Power Law Scheme. The grids are generated with an elliptic grid generator using control functions. The results compare favorably with those by Oxford wind tunnel measurements.

关键词： numerical simulation wind loads building

Simulation Technology in System Optinuzation:Method and Application

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Journal of Modern Transportation 1995年第1期12卷 33-40页

作者： Hu pei(School of Eoonomics and Management,southwest jiaotong university, chengdu 610031, china)

Combining simulation technology with optimization method, this pepar discussesprocess and steps of simulation applied to system optimization, especially,studies technology and method of constructing system model,and evaluationand verification of the model. As an application, a digging-transperting-producing ensineering is simulated and optimized by using SIMAN/CINEMA.

关键词： simulation system model,optimization

Uniquely　Tree　Colorable　Graphs

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Journal of Modern Transportation 1997年第1期14卷 90-95页

作者： Deng Ping Department of Applied Mathematics, southwest jiaotong university, chengdu 610031, china

In this paper, the concepts of tree chromatic numbers and uniquely tree colorable graphs are introduced. After discussion some fundamental properties, three necessary conditions for a simple graph to be uniquely tr... 详细信息

关键词： tree chromatic number tree partition uniquely tree colorable graph

NumericalAnalysisforBucklingandPost─BucklingBehaviorofPlanarFrames

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Journal of Modern Transportation 1996年第1期13卷 68-78页

作者： Wang Xiaochun Institute of Applied Mechanics, southwest jiaotong university, chengdu 610031, china

Research on the problem of buckling and post buckling for structures is one of noticed directions in the field of engineering mechanics at present. Whether from the aspect of theory or from the aspect of numerical method, it is necessary to have a deep research on the problem. In this paper, a new geometrical nonlinear element and numerical implementation were presented. By some examples, the problem of buckling and post bukling for planar frames subjected to given loads was discussed in detail.

关键词： planar frame buckling post buckling finite element numerical analysis

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虚拟环境选线系统中的知识表达模式

铁道学报 2004年第1期26卷 88-92页

作者：易思蓉西南交通大学道路与铁道工程系四川成都610031

知识表达模式是虚拟环境选线设计系统实现智能功能的关键部分。本文首先从分析铁路线路走向选择的相关因素入手 ,探讨了选线领域知识的体系结构。在分析领域知识特点的基础上 ,提出面向对象类规则知识表达模式 ,并将此方法用于表达铁路... 详细信息

知识表达模式是虚拟环境选线设计系统实现智能功能的关键部分。本文首先从分析铁路线路走向选择的相关因素入手 ,探讨了选线领域知识的体系结构。在分析领域知识特点的基础上 ,提出面向对象类规则知识表达模式 ,并将此方法用于表达铁路选线设计领域知识。实例证明 ,本文提出的类规则知识表达模式 ,将产生式规则知识表达法与面向对象技术相结合。

关键词：铁路选线知识表达虚拟环境面向对象

CoronaRegimeofDualBarAgainstPlane

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Journal of Modern Transportation 1996年第1期13卷 61-67页

作者： Xu Guozhong Department of Applied Physics, southwest jiaotong university, chengdu 610031, china

The aim of this paper is to study the behaviour of bipolar corona with a dual parallel corona bar and a metallic plate. The experimental results show that under otherwise identical conditions, the discharge depends strongly on the electrode separation between the bars. By investigating various separations, the corona regime can be divided into three regions: independent, shunted, and shorted. The criterion for eliminating electrostatic charge without over compensation is also given.

关键词： corona discharge dual electrode system electrostatic charge eliminator

THEORETICAL STUDIES ON MICROBUCKLING MODE OF ELASTIC MEMORY COMPOSITES

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Acta Mechanica Solida Sinica 2010年第1期23卷 20-28页

作者： Zhengdao Wang Zhengfa Li Zhiyuan Xiong Linyun Wang(Department of Mechanics,School of civil engineering,Beijing jiaotong university,Beijing 100044,china) [a] Department of Mechanics School of Civil Engineering Beijing Jiaotong University Beijing 100044 China

Elastic memory composites （EMCs） have great potential applications in future deployable space structures due to their high packaging strain and shape memory characteristics. Microbuckling of compressed fibers is the primary deformation mechanism of such structures to receive a higher packaging strain than that of traditional fiber-reinforced composites. In order to have a better understanding of such deformation mechanism, the microbuckling model of EMC laminates under bending is analyzed firstly. Then the theoretical critical microbuckling parameters are predicted, which are compared with experimental observations and other models.

关键词： elastic memory composite deployable structure microbuckling model