桁架结构

Steel Truss.It is the load-bearing part in the roof structure. It can be triangle, trapezoid, shuttle and three-hinged. Angle bar steel, thin steel sheet, round bar and square bar can be used to manufacture it.

桁架：桁架是屋盖结构中主要承重构件，桁架的形式有三角形，梯形，梭形，三铰捞等，可采用角钢薄壁型钢，园管，方管等来制作。

The variable geometry truss mechanisms have been studied extensively and systematically by this project. The research plan has been completed all sidedly, and expected results have been obtained. Three new kinds of combination decahedrons and a new class of variable geometry truss mechanism, which is composed of an octahedron and three tetrahedrons connected in parallel form, are proposed. The position analyses for decahedrons, dodecahedrons, triple-octahedrons, combinations decahedron and a new type of structure of variable geometry truss mechanisms are presented by introducing additional extra linear displacement sensors and using resultant elimination and homotopy continuation algorithms. The method of kinematical analysis of variable geometry truss mechanisms is established.

课题组对变几何桁架机构进行了深入的研究，全面地完成了研究计划，取得了预期的成果；提出了三种新的十面体组合机构以及由一个八面体和三个四面体组成的新型变几何桁架机构的结构形式；应用结式消元、附加传感器和同伦方法等提出了十面体、十二面体、三重八面体、组合十面体和新型变几何桁架机构的位置分析方法；建立了变几何桁架机构运动分析的一般方法；建立了简洁的凯恩和拉格伦日动力学的模型；应用有限元和子结构方法，提出了变几何柞架机构弹性动力学模型，导出了逆动力学方程的显式形式；设计和研制了一台可折叠的八面体变几何杵架机构装置等。

Part two: This paper attempt to design a retractable roof structure from architectu re,structure and mechanism in the kind of traveling trusses and flexible roofage thro ugh a real structure of the retractable roof in the walk street plaza of Henglong build ing. Summary of some important points in design were presented.The comparision of several kinds of structure was taked.

第二部分：本文以恒隆步行街广场屋盖工程为例，通过对比分析剪刀撑方式、倒三角桁架式和张弦梁形式的结构方案，最终选择了倒三角桁架式的可展桁架加柔性屋面材料的方案。

The role of truss in staggered steel truss system and characteristics of all kinds of truss forms were introduced?

介绍了桁架在钢结构交错桁架体系中的作用及各种桁架形式的特点。

In this model, axial yarns, braider yarns and resin were treated as spatial beam elements. Each unit cell is then treaded as space truss.

其中，轴纱、编织纱和基体均被视为两端铰接的空间杆单元，复合材料用离散的杆单元组成的桁架结构代替。

As one of the most forelands in space structure, present study on prestressed spatial truss string structure is short of exhaustion and systematicness.

张弦立体桁架结构作为我国空间结构领域的前沿课题之一，目前对其还缺乏全面系统的研究工作。

Based on maximum entropy two-stage optimization design theory, maximum entropy two-stage optimization design system including truss, beam, frame structures is founded in this thesis.

本文从两相优化的理论出发，研究了基于最大熵准则的桁架、梁和框架结构最小材耗问题，系统地建立了包括桁架、梁、框架结构在内的各主要土木建筑基于最大熵的结构两相优化设计理论构架体系。

Transmission tower is a large structure of space truss, To made it needs a great deal of steels.

输电铁塔是大型的空间桁架结构，需要大量的钢材建造。

The application of genetic algorithm in optimization design of structures with discrete variables is presented with an example of optimization design for three-bar hyper static truss structures with discrete variables.

以三杆桁架结构优化设计演示了遗传算法在离散变量优化设计中的应用。

The closed ring confining truss is set along the periphery of the reticulated shell, and the stiffening truss is set in the middle single-layer shell which can take advantage of the architectural shape. These measures resolve the contradiction between overall stability and temperature stress, and also avoid the shell thrust act on the lower concrete structure directly. Besides, these measures simplify the design of the shell bearing and the concrete structure, and the cost of the concrete structure can also be saved.

网壳通过可径向滑动球铰支座与下部混凝土结构连接，网壳周边设置封闭环形约束桁架，中间单层壳体部分利用建筑凸肋造型设置加劲桁架，解决了保证整体稳定和减小温度应力之间的矛盾，同时避免了网壳侧推力直接传递给下部混凝土结构，简化了网壳支座及下部混凝土结构的设计，节约了混凝土结构的造价。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。