检索结果-南通市图书馆

Configuration synthesis of planar folded and common overconstrained spatial rectangular pyramid deployable Truss units

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第7期32卷 1772-1787页

作者： Hui YANG Hongwei GUO Yan WANG Rongqiang LIU Zongquan DENG College of Electrical Engineering and Automation Anhui UniversityHefei230601China State Key Laboratory Robotics and System Harbin Institute of TechnologyHarbin150001China China Electronics Technology Group Corporation No.38Research Hefei230088China

Compared with non-overconstrained deployable units, overconstrained deployable units are widely used in space missions for their higher stiffness characteristics. Besides the performance of a three-step topological structural analysis and design of the rectangular pyramid deployable Truss unit(PDTU), conducting a structural synthesis of an overconstrained deployable unit requires the determination of the relative position and direction of each kinematic axis. The structural synthesis of an overconstrained deployable unit is investigated based on screw theory and its topological structure. The possible overconstrained cases of the rectangular PDTUs are analyzed, and corresponding screw expressions are obtained. Thus, the rectangular PDTUs, which can be folded into a plane, are synthesized systemically, and a series of overconstrained rectangular PDTUs is obtained. Furthermore, the feasibility of the folded and deployed motions under one degree of freedom for those deployable units is verified in dynamical simulation by using ADAMS 2010.

关键词： Assembly SAR antenna Common overconstraint Deployable Truss structure Screw theory Structural synthesis

A review on application of composite Truss bridges composed of hollow structural section members

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2019年第1期6卷 94-108页

作者： Zhijuan Tian Yongjian Liu Lei Jiang Weiqing Zhu Yinping Ma School of Highway Chang'an University Department of Civil Engineering Queen's University

Composite Truss with hollow structural section(HSS) members is deemed as the structure applicable to large-span and heavily-loaded bridges. To promote the application of composite Truss bridge with HSS members in China, this paper described its structural characteristics and technology in details. Besides, not only were 32 typical design cases of composite Truss bridges with HSS members collected, but also the corresponding historical development was summed up. Comparisons on structural components, characteristics and engineering applications were made among composite Truss bridges with HSS members in different structural forms. Then, the analysis on the characteristics of composite Truss bridges with concrete-filled steel tubular(CFST) chords was conducted, and the challenges on the aspects of complicated joints and interfacial debonding were pointed out. To address these problems, the concrete-filled rectangular hollow section(CFRHS)stiffened with PBLs(Perfobond Ribs) was proposed to improve the reliability of confinement effect in CFST member and force transfer in joints. The advantages on the mechanical properties of CFRHS structure stiffened using PBLs were systematically expounded with respect to the behaviors of steel plate, interface, member and joint. Moreover, the structure design, construction technology, structural calculation and economic efficiency of the practical bridge with CFRHS chords stiffened using PBLs were comprehensively analyzed.The results demonstrated that composite Truss bridge with PBL-stiffened CFRHS members was competitive in mechanical performance and construction.

关键词： Composite Truss bridge Rectangular hollow section Concrete-filled Perfobond rib

Nonlinear analysis and reliability of metallic Truss structures

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2018年第4期12卷 577-593页

作者： Karim BENYAHI Youcef BOUAFIA Salma BARBOURA Mohand Said KACHI LaMoMs Laboratory University Mouloud Mammeri of Tizi-Ouzou15000Tizi-OuzouAlgeria C.N.R.S.LSPM-UPR 3407Laboratory Paris13UniversityParisFrance

The present study goes into the search for the safety domain of civil engineering structures. The objective is to show how a reliability-evaluation brought by a mechanical sizing can be obtained. For that purpose, it is necessary to have a mechanical model and a reliability model representing correctly the behavior of this type of structure. It is a question on one hand, to propose a formulation for the nonlinear calculation (mechanical nonlinearity) of the spatial structures in Trusses, and on the other hand, to propose or to adapt a formulation and a modeling of the reliability. The principle of Hasofer-Lind can be applied, in first approach, for the reliability index estimation, scenarios and the probability of failure. The made check concerned metallic in Truss structures. Finally, some structures are calculated using the method adapted by Hasofer-Lind to validate the probability approach of the reliability analysis.

关键词： modeling nonlinearity mechanical Truss probability reliability response surface probability of failure

有向图上的最大Truss社区搜索研究与应用

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

有向图上的最大truss社区搜索研究与应用

作者：张纯鹤沈阳航空航天大学

学位级别：硕士

社区搜索问题是指在给定的图数据中,找到所有包含查询顶点的密集连接的子图。Truss是一种基于三角形结构的社区搜索模型,被用于搜索k-Truss社区。有向图上最大Truss社区搜索研究工作在实际应用中具有广泛的应用价值,然而在有向图上,现... 详细信息

社区搜索问题是指在给定的图数据中,找到所有包含查询顶点的密集连接的子图。Truss是一种基于三角形结构的社区搜索模型,被用于搜索k-Truss社区。有向图上最大Truss社区搜索研究工作在实际应用中具有广泛的应用价值,然而在有向图上,现有的基于索引的Truss社区搜索方法存在索引空间大、搜索效率低、社区内聚性低的缺点。为了解决这一问题,文中研究了在有向图上基于Truss模型的最大社区搜索问题,研究内容分为最大kc-cycle Truss社区搜索和最大kf-flow Truss社区搜索,可以帮助揭示复杂网络中的社区结构,对于理解网络的功能、组织和演化过程具有重要意义。首先解决了有向图上的最大kc-cycle Truss社区搜索问题,kc-cycle Truss社区是一种基于cycle三角形的社区结构,文中设计一种cycle Truss分解算法,并提出了两个重要的概念:cycle三角形连通和kc-层次等价。基于kc-层次等价设计了层次树索引Tree CIndex和表结构索引Super Table,并基于这两个新的索引,设计了两种高效的cycle Truss社区搜索算法,与传统的对有向图进行大量耗时访问的社区搜索算法不同,文中提出的cycle Truss社区搜索算法仅需访问层次树索引Tree CIndex与表结构索引Super Table即可搜索出最大cycle Truss社区,提高了社区搜索效率。接着解决了有向图上的最大kf-flow Truss社区搜索问题,kf-flow Truss模型是一种基于flow三角形的社区结构,文中提出了社区内查询顶点能够访问任意其他顶点的概念,从而提高社区的内聚性,然后设计了一种基于flow Truss分解的索引Flow Index,并设计了基于Flow Index的社区搜索算法。文中提出的算法通过剪枝的策略,减少了访问与社区不相关的边的次数,提升了搜索效率。在四个真实数据集上将文中提出的算法与已有的基于Truss Index与Equi Truss的社区搜索算法进行了比较,实验结果表明,Tree CIndex与Super Table比Truss Index与Equi Truss的索引占用空间节省至少41.5%,索引构建的时间节省8.2%至98.3%,且搜索最大kc-cycle Truss社区的效率提升了一至两个数量级。Flow Index算法比Truss Index算法搜索最大kf-flow Truss社区的效率提升了一个数量级。

关键词：社区搜索 Truss 有向图 cycle三角形 flow三角形

基于小波分析的Spar平台阻尼系数研究（英文）

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

船舶力学 2015年第9期19卷 1085-1096页

作者：张蕙杨建民肖龙飞吕海宁上海交通大学海洋工程国家重点实验室上海200240

连续小波分析方法作为典型的时频方法虽已广泛应用于工程界,但在海洋工程领域并未得到大力推广。文章应用连续小波分析方法对海洋工程领域中与Truss Spar平台涡激运动相关的阻尼系数进行求解。通过构建测试信号对这一方法进行数值检验,... 详细信息

连续小波分析方法作为典型的时频方法虽已广泛应用于工程界,但在海洋工程领域并未得到大力推广。文章应用连续小波分析方法对海洋工程领域中与Truss Spar平台涡激运动相关的阻尼系数进行求解。通过构建测试信号对这一方法进行数值检验,验证了小波分析方法的可靠性和准确性。利用试验数据,成功将小波分析方法应用于求解Truss Spar平台阻尼系数问题中。结果表明小波分析方法具有较好的可靠性,能够准确求解平台的阻尼系数。

关键词：连续小波分析阻尼系数涡激运动 Truss Spar

基于细长体公式的Truss SPAR在波流中的运动响应预报方法

在线全文

学校读者我要写书评

暂无评论

船舶工程 2018年第3期40卷 78-81,85页

作者：许国春石凡宁波大学海运学院浙江宁波315211

利用细长体公式和刚体非线性运动方程建立Truss SPAR在波流中的运动响应预报方法。通过波浪自由表面和Truss SPAR中心线方程构造辅助函数,迭代计算瞬时湿长度。根据Truss SPAR主体形状特点和流场中水质点运动规律,分段高效积分水动力载... 详细信息

利用细长体公式和刚体非线性运动方程建立Truss SPAR在波流中的运动响应预报方法。通过波浪自由表面和Truss SPAR中心线方程构造辅助函数,迭代计算瞬时湿长度。根据Truss SPAR主体形状特点和流场中水质点运动规律,分段高效积分水动力载荷。通过Runge-Kutta-Fehlberg方法求解运动方程,得到Truss SPAR在波流中的运动响应。对一座Truss SPAR在不同波流工况中的运动响应进行预报,结果表明,波浪和流使Truss SPAR产生明显漂移运动和振荡运动,漂移运动的大小与流向有关,而振荡运动的幅值与波浪方向有关。

关键词：细长体公式 Truss SPAR 运动响应预报

Truss Spar平台在船舶碰撞下的数值模拟分析

在线全文

学校读者我要写书评

暂无评论

舰船科学技术 2018年第11期40卷 60-65页

作者：汪宏明杉杉杨浩冯森徐同达夏兰强江苏科技大学船舶与海洋工程学院江苏镇江212003

海洋平台在海上进行工程作业时除了遭受恶劣的环境载荷外,还可能与海上船舶发生碰撞。为探究Spar平台在遭受船舶碰撞后的动力响应,本文选取1座墨西哥湾的Truss Spar平台,运用有限元分析软件Ansys/Lsdyna,建立5 000吨级补给船与Truss Spa... 详细信息

海洋平台在海上进行工程作业时除了遭受恶劣的环境载荷外,还可能与海上船舶发生碰撞。为探究Spar平台在遭受船舶碰撞后的动力响应,本文选取1座墨西哥湾的Truss Spar平台,运用有限元分析软件Ansys/Lsdyna,建立5 000吨级补给船与Truss Spar平台的有限元模型并模拟碰撞过程,得到船舶在不同速度下与Spar平台碰撞过程中的能量转化情况和船舶撞击力时程曲线,通过对结果的分析得出一般性规律和结论,为Spar平台的设计提供理论参考依据。

关键词： Truss Spar平台 Ls-dyna 碰撞力数值模拟

Effect of Elastic Modulus on Maximum Displacement Response of Truss Structure

在线全文

学校读者我要写书评

暂无评论

Effect of Elastic Modulus on Maximum Displacement Response o...

Equivalent continuum modeling of beam-like Truss structures with flexible joints

作者： Xin-yang CHEN Zu-ping MENG School of Aeronautics and Astronautics Sun Yat-sen University School of Civil Engineering Chiao Tung University

Dynamic stress and displacement of Truss are directly related to the safety of Truss in case of impact loading of the Truss structure. Elastic modulus is an important parameter which has an effect on the dynamic stress and displacement in Truss structure. Analyzing the effect of elastic modulus on dynamic mechanics can provide the design criterion for Truss structure. Here, a 3D simulated method on the basis of finite element model（FEM） was proposed to analyze the dynamic stress and displacement of the Truss structure under impact loading. By means of the simulated method, the effect of elastic modulus on the maximum displacement was investigated. Via exporting the corresponding mechanical response, the maximum displacements are plotted in one figure to analyze the effect of elastic modulus on dynamic mechanical response. The maximum displacement could increase when the elastic modulus is raising. Meanwhile, the maximum displacement increases with the elastic modulus in nonlinear pattern.

关键词： Truss Elastic modulus Finite element model Maximum displacement

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2019年第5期35卷 1067-1078页

作者： Fushou Liu Libin Wang Dongping Jin Hao Wen College of Civil Engineering Nanjing Forestry UniversityNanjing 210037China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The paper investigated the equivalent continuum modeling of beam-like repetitive Truss structures considering the flexibility of joints,which models the contact between the Truss member and joint by spring-damper with six directional stiffnesses and dampings.Firstly,a two-node hybrid joint-beam element was derived for modeling the Truss member with flexible end joints,and a condensed model for the repeating element with flexible joints was obtained.Then,the energy equivalence method was adopted to equivalently model the Truss structure with flexible joints and material damping as a spatial viscoelastic anisotropic beam model.Afterwards,the equations of motion for the equivalent beam model were derived and solved analytically in the frequency domain.In the numerical studies,the correctness of the presented method was verified by comparisons of the natural frequencies and frequency responses evaluated by the equivalent beam model with the results of the finite element method model.

关键词： Large space Truss structure Flexible joint Equivalent continuum modeling Anisotropic beam model Frequency response