桁架结构

The (0,1) placement variables are treated as continuous variables and then rounded after the optimization. The computational formula of the sensitivities of the freevibration frequency with respect to placement variables is derived.

在压电材料组成的桁架结构的自由振动频率优化设计中，提出了压电杆件配置的(0，1)设计变量并将其连续化处理，推导了压电桁架自振频率对该设计变量的灵敏度计算方法。

The concept of topology optimization of truss structures with discrete variables including two kinds of variables and the relative difference quotient algorithm for discrete optimization are extended to the topology optimization of plate and shell structures composed by plate and shell elements.

将包含两类变量的桁架结构拓扑优化设计的概念及求解离散优化的相对差商法进一步推广到由板壳单元组成的板壳结构的拓扑优化，建立了包含两类变量的板壳结构拓扑优化设计模型，并采用相对差商算法进行求解。

In this paper,the structure ecotype,the structural characteristics and the method to deal with horizon thrust force are introduced.

本文简单论述了该工程中的结构选型、受力特点和水平推力的处理方法，并根据本工程提出了设计空间桁架结构时应该注意的一些问题

The dynamic characteristics of stochastic truss structures and stochastic frame structures are analyzed by using Random Factor Method. Then, from the expressions of structural random response of the frequency domain, the computational expressions of the mean value, variance and variation coefficient of the mean square value of the structural displacement and stress response under the stationary random excitation or non-stationary random excitation are developed by means of the random variable's functional moment method and the algebra synthesis method.

考虑压电智能桁架结构物理参数、几何参数、结构阻尼和外荷载、闭环系统控制电压分别或同时为随机变量，构建了结构在随机力作用下的动力响应分析模型，提出了求解方法，推导出结构动力响应随机变量的数字特征计算表达式，通过算例验证了所建模型和所提求解方法的正确性和有效性。

On the basis of the improved structure and under the premise of meeting specification requirement, the light steel door-truss structure is optimally designed by changing, cycle checking and gradually reducing the cross section size of overall structural member with the ANSYS parametric design language. The mechanical properties such as changes in stiffness, strength and stability of the optimized structure are completely analyzed under three load cases.

基于改进结构，在满足相关规范的前提下，利用ANSYS软件的参数化命令流语言（ANSYS parametric design language， APDL），通过改变结构杆件截面尺寸，对整体结构杆件的截面采用循环校核、递减尺寸，并对轻钢门式桁架结构进行优化设计，分析了优化结构在3种荷载工况组合条件下的整体刚度、强度及稳定性等力学性能的变化，给出了改进前后与优化前后结构的力学特性对比。

In study of the truss structural dynamic characteristics analysis, randomness of the structural physical parameters and geomtric ones are all considered. The finite element model of the stochastic truss is built and the random functions of its natural frequencies are obtained by use of the Rayleigh quotient. Employing probabilistic distribution function expression for the random functions, through a series of mathematical processing including determination of limits of integrals, variable substitution etc., the probaabilistic density function for the truss natural frequencies are gained to realige accurate calculation for the reliability of the truss natural frequencies.

考虑结构物理参数和几何参数的随机性，通过构建随机参数桁架结构的有限元模型，利用瑞利商公式获得了结构固有频率随机函数的计算表达式，应用随机函数的概率分布函数表达式，通过确定积分区间、变量替换、积分顺序变换等一系列数学上的处理，获得结构固有频率的概率密度函数，进而实现对结构固有频率可靠度的精确计算。

To meet the challenge of the design for different span projects, the influence of the major parameters on the mechanical behavior at different spans is analyzed in this paper. The variation rule of these parameters with the span is discussed in this paper, which provides thereunder for project designs.

4为满足实际工程中不同跨度的设计需求，本文针对张弦立体桁架结构的主要参数在不同跨度时对结构的受力性能影响情况进行了计算分析，讨论了结构参数和跨度二者之间的变化规律，为工程设计提供了参数选择的依据。

2The static behavior of one prestressed spatial truss string structure is analyzed systematically in this paper. The change of the structural internal forces and displacements with the rise-to-span ratio, sag ratio, prestress and the number of brace struts is studied and the influence of these parameters on the mechanical behavior is discussed compressively in detail.

2对一张弦立体桁架结构的静力性能做了系统分析，研究了结构的内力和位移在矢跨比、垂跨比、预应力和撑杆数不同参数下的变化情况，全面详细的探讨了结构的主要参数对结构静力性能的影响。

Fish-bellied cable truss of point supported glazing has been widely used for the characters of lightness and transparency. And commonly it is systematically supported, when additional support is added, the structure is turned from symmetrical support into unsymmetrical support, the mechanical performance will be changed greatly because of its weak ability to resist unsymmetrical deformation, and more discussion will be needed.

点支式玻璃幕墙鱼腹式索桁架结构由于其轻盈、通透的特点得到了广泛的应用，其一般都是对称支承布置，当结构由对称支承变为非对称支承时，由于其抵抗不对称变形的能力较弱，结构的力学性能会发生较大的改变，需要作进一步的探讨。

In this paper,a nonlinear planning method, quasi Newton multiplier method ,is introduced for the optimization of the bracing stiffness in braced frame structures with symmetric bracings.

本文针对设置有对称斜腹杆的钢筋混凝土框架－桁架结构，运用非线性规划方法拟牛顿乘子法，对框架－桁架结构体系中斜撑的刚度进行优化。

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。