板柱结构具有可利用空间大、布局灵活、显著降低层高等优势,但是存在结构水平刚度较弱、位移大、抗震承载力较差等问题.为解决上述问题,在板柱结构中设置屈曲约束支撑,以提高结构的抗侧刚度,增强其抗震承载力.通过对3个高度不同和2个大面积的板柱-支撑结构的计算表明,板柱结构抗侧刚度和承载力较弱的问题可通过设置适当数量的屈曲约束支撑解决.为研究板柱-支撑结构的变形、层间剪力、倾覆弯矩、支撑布置等问题,通过PKPM建模分析,结果表明:多遇地震作用下,板柱-支撑结构可采用框架结构的弹性层间位移角(1/550)来控制结构变形;板柱-支撑结构中支撑承担的楼层剪力建议不低于楼层剪力的40％;通过对比GB 50011-2010《建筑抗震设计规范》和力学概念计算得到楼层倾覆力矩的结果,认为采用规范建议的方法较为合理;支撑的竖向居中布置会减小支撑倾覆力矩占比,而对支撑剪力占比影响较小.

The flat plate system, as a popular structure in concrete buildings, still requires improvement in slab-column connections, which are the most vulnerable areas from the point of view of safety. Over the last few decades, various methods of shear reinforcement have evolved around the world. However, the hysteretic performance and bearing capacity of those methods may not provide absolute guarantees. The conventional concrete capital referred to herein resembles a truncated pyramid, which has the disadvantage of requiring a large space. This paper proposes a new technique- steel capital, which applies steel plates, channel steel, and shear bolts. An experiment of three specimens-one with conventional concrete capital, one with steel capital, and one control specimen- was conducted. The failure mode, hysteretic loops, skeleton curve, bearing capacity, stiffness, ductility, and deformation of the three specimens are presented in this paper: The results indicate that the steel capital can effectively increase the bearing capacity and stiffness of the slab-column structure. Steel capital should be considered in the strengthening and design of slab-column structures.

Buckling restrained braces have dual functions of both providing lateral stiffness and improving seismic performance under earthquake in an economic and flexible way. To strengthen the performance of slab-column system, chevron buckling restrained braces were applied at slab-column connections. A quasi-static test on a one-half scale, one-bay and one-story model was conducted to evaluate the seismic performance of the slab-column frame with chevron buckling restrained braces. The results show that the cracks are mainly located in the range of 1 /3 slab length around both columns and lower 1 /3 of the column height,which are also the most severely damaged locations. The specimen still has bearing capacity when the deflection angle reaches 1 /50. The model finally fails due to the failure of tensile brace in the loading process of deflection angle 1 /30 (50 mm displacement). Adopting ABAQUS finite element method,skeleton curves and plastic damage of slab-column structures with and without chevron buckling restrained braces were compared. According to the experiment and FEM simulation results,the chevron buckling restrained braces can effectively increase the lateral bearing capacity and lateral stiffness of slab-column structure,which should be considered in design and strengthening of slab-column structure.

The paper proposes a set of indicators of anti-swing effect for crane hook, analyzes the influence of dominant control parameters of the anti-swing system for bridge crane use on the anti-swing effect and its design method, sums up the core dominant parameters related to the anti-swing control method, and analyzes theoretically the method of determining parameters and value range. The final part is experiment on the prototype bridge crane and quantitative description of the influence of parameter value on anti-swing effect on the basis of the said indicators of anti-swing effect. The experimental results are in good agreement with the conclusions from theoretical analysis, thus proving that the theoretical design method of control parameters is correct.

Flat plate structure has grown to be one of the most popular forms of construction.However,the slab-column connection is easily failed by punching shear because of limited lateral stiffness and lateral capacity.The brittle punching shear failure can be occurred especially for the shear force and unbalanced moment under earthquake,which may even cause progressive collapse of buildings.The examples of damaged flat plate buildings due to earthquake are introduced in detail and the main reasons of those failure and damage are analyzed.Moreover,new progress in research on the seismic performance of flat plate system and slab column connection is presented.To improve the punching shear resistance capacity of the slab column connection,the most common methods are demonstrated,for instance,the use of shear reinforcement,increase of strength and ratio of reinforcement,application of steel fiber reinforcement and high strength concrete and use of shear capital or drop panel.Application and standardization of flat plate structure in China are also introduced.Finally,the challenges in relevant research and promotion of flat plate structure are suggested.

桥式起重机大车运行在考虑弹性结构情况下,起重机主梁会产生垂向变形和横向变形。传统的双质量两自由度系统模型是把桥式起重机的运行机构假象为刚性结构,而横向变形会对防摇控制数学模型的精确性产生影响。分析横向变形对防摇控制模型的影响,建立桥式起重机三个质量三个自由度串联弹性动力学系统振动模型并基于MATLAB进行仿真对比,得到三质量系统下吊重摆角曲线,随后与传统的双质量系统进行比较,得到摆角误差曲线,进行对比分析可得,三质量系统相比双质量系统提高了模型精度。

为克服传统基结构设计方法对最优解的束缚,实现桁架结构的拓扑布局及尺寸优化,提出了将连续体与离散杆系相结合的桁架结构优化设计方法.从连续体出发,基于SKO连续体拓扑优化方法得到了最优拓扑布局;以二值图像细化算法为基础,提出了基于有限单元8邻域网格模型的骨架提取算法,通过剥离冗余单元,得到了连续体拓扑优化结果的中心传力骨架;以单元主应力为判据,精确找到骨架中的关键点,并连接关键点形成了初始桁架结构;基于拉格朗日乘数法和Kuhn-Tucker条件,以初始桁架中杆件的内外半径为设计变量,结构体积为约束条件,结构柔度为目标函数,建立了桁架结构杆件尺寸优化的数学模型,并推导出其优化迭代准则.最后,以一悬臂结构为例对该优化方法的应用进行了说明,并使用一经典算例与其他文献中的方法进行了对比,结果表明:该优化方法得到的桁架结构具有优化的拓扑构型和力学特性,杆件布局、尺寸合理,应力均匀.

带填充墙历史建筑钢框架的低周反复加载试验表明,钢柱外包砖、填充墙能显著提高框架抗震承载能力和抗侧刚度.在此基础上,采用ABAQUS软件建立单层单跨带填充墙钢框架三维实体模型,进一步分析其在水平荷载作用下的受力性能,数值模拟结果与试验结果较吻合.有限元分析发现,钢框架达到承载能力极限状态时钢柱及其外包砌体、填充墙的贡献近似等于各自的极限承载能力.参数分析结果表明,填充墙宽度增大,墙体承载力贡献提高,但其抗剪强度下降,不能简单地根据抗剪面积计算填充墙承载力贡献.此外,随着填充墙厚度的增加和砂浆强度的提高,填充墙的承载力贡献增加.将该类历史建筑中填充墙框架看作带斜撑钢框架,假定钢柱与外包砌体协同工作,建立了抗剪承载力的简化计算公式.