钢桁架连梁-联肢剪力墙耗能机理及抗震性能试验研究

对设置全钢桁架连梁和设置钢筋混凝土、钢桁架混合连梁的双层联肢剪力墙平面结构进行了拟动力试验和低周反复荷载试验,研究了不同工况地震波作用下剪力墙的时程响应,以及其破坏机理、承载力、滞回延性性能、耗能机理、刚度及强度退化机理。试验结果表明：全部设置钢桁架连梁的剪力墙的刚度分布合理,耗能机理及刚度强度退化机理符合联肢剪力墙抗震设计的要求。大震时,在保证较高耗能能力的同时能够维持较高的承载力和刚度,持续约束墙肢,抗震性能优于混凝土连梁联肢剪力墙体系,是一种较理想的连梁设置方案。     

双环可展桁架结构动力学分析与试验研究

基于广义逆矩阵方法分析双环可展桁架的运动过程,通过数值仿真,得出双环可展桁架在展开过程中的各个状态.经过对比分析可知,对于大口径天线,双环可展桁架的刚度可以比同口径单环可展桁架明显增加.利用上述仿真程序输出的几何模型,进一步对50m双环可展桁架原型建立有限元模型,并进行展开过程中各状态的振动模态分析.对2m天线试验样机采取悬挂法消除重力影响并进行振动模态试验,且将其与有限元计算结果对比,结果表明两者的频率较为接近,验证了有限元动力学分析的正确性.     

Dynamic Response Analysis of Fuzzy Stochastic Truss Structures under Fuzzy Stochastic Excitation

A novel method (Fuzzy factor method) is presented, which is used in the dynamic response analysis of fuzzy stochastic truss structures under fuzzy stochastic step loads. Considering the fuzzy randomness of structural physical parameters, geometric dimensions and the amplitudes of step loads simultaneously, fuzzy stochastic dynamic response of the truss structures is developed using the mode superposition method and fuzzy factor method. The fuzzy numerical characteristics of dynamic response are then obtained by using the random variable’s moment method and the algebra synthesis method. The influences of the fuzzy randomness of structural physical parameters, geometric dimensions and step load on the fuzzy randomness of the dynamic response are demonstrated via an engineering example, and Monte-Carlo method is used to simulate this example, verifying the feasibility and validity of the modeling and method given in this paper.     

带悬挂吊车的钢桁架结构设计

通过某企业集团装配厂房的设计实践,对设有吊车梁悬挂支座的钢桁架结构在吊车荷载作用下的内力分析、截面选择、节点设计、变形计算以及支撑布置等进行了介绍和探讨,提出了设计中应注意的关键问题及相应解决措施.     

Extending the Fatigue Life of Riveted Coped Stringer Connections

Fatigue cracking occurs at the copes of stringer–floorbeam connections of older, riveted steel bridges. Some cracks are quite long and raise serious questions regarding the remaining fatigue life of the subject bridges. Damage limitation methods (DLMs) have been used to increase the fatigue life of these stringers, but the effectiveness of the DLMs for these riveted connections had never been evaluated by tests. Therefore, tests were conducted to evaluate the fatigue life of coped, riveted stringer–floorbeam connections, and the effectiveness of DLMs. Fatigue cracks in the coped stringer–floorbeam connection were initially developed to establish crack initiation requirements and the rate and extent of crack growth. Once a significant crack was noted, one of several DLMs was applied, and the specimens were retested to determine the effectiveness of the DLM in controlling cracking. These DLMs included the drilled hole, the inserted bolt and the removed rivet methods. The relative effectiveness of the methods is described, and a design procedure is proposed for improving their performance.     

刚架拱桥及桁架拱桥的设计与受力特征分析

介绍了刚架拱桥及桁架拱桥在阜阳市的应用及其型式、构造、设计和受力特征分析     

线性随机智能桁架结构闭环动力响应

不仅压电智能桁架结构的阻尼、物理参数、几何尺寸具有随机性，而且外载荷幅信、闭环系统控制电压同时具有随机性时，利用振型迭加法导出了结构动力响应随机变量的数字特征计算表达式．算例表明文中所提出的动力响应分析模型和方法是合理可行的．     

预应力空间网架结构一次张拉计算法

反复张拉和反复调整预应力杆的内力是目前工程上常用的施工方法，该方法十分麻烦且费时费钱．为此提出了预应力空间网架结构一次张拉计算法，将逐次增加预应力杆的预应力值作为未知数，通过结构力学方法，建立预应力准则方程式并求解之；然后计算每次预应力时各预应力杆的控制值、后张预应力对先张预应力杆的影响值，以及网架结构杆件内力和节点变位，直至最后一次预应力时，得到各预应力杆的最终设计内力值及网架结构的内力和变位．采用本文方法对文中算例的计算结果说明，预应力杆的内力值在预应力张拉全过程中无须调整，可一次性完成预应力施加的操作过程．     

Optimization of practical trusses with constraints on eigenfrequencies, displacements, stresses, and buckling

In this paper we consider the optimization of general 3D truss structures. The design variables are the cross-sections of the truss bars together with the joint coordinates, and are considered to be continuous variables. Using these design variables we simultaneously carry out size optimization (areas) and shape optimization (joint positions). Topology optimization (removal and introduction of bars) is only considered in the sense that bars of minimum cross-sectional area will have a negligible influence on the performance of the structure. The structures are subjected to multiple load cases and the objective of the optimizations is minimum mass with constraints on (possibly multiple) eigenfrequencies, displacements, and stresses. For the case of stress constraints, we deal differently with tensile and compressive stresses, for which we control buckling on the element level. The stress constraints are imposed in correlation with industrial standards, to make the optimized designs valuable from a practical point of view. The optimization problem is solved using SLP (Sequential Linear Programming).     

重载轻型桁架斜拉式组合挂篮的研究

主要介绍了重载轻型桁架斜拉式组合挂篮的结构形式、特点，分析了其计算模型，并通过工程算例的验证，表明了该种挂篮结构合理、构思独特．与其它结构形式的挂篮相比，它受力较为均匀、节省材料、减轻自重，是一种较为理想的新型挂篮结构，有实际应用价值．