半刚接钢框架稳定分析中柱的计算长度取值研究

根据钢框架稳定设计中柱子计算长度的概念 ,研究了钢框架中梁柱节点半刚接柱的计算长度系数取值问题 ,采用螺旋弹簧模拟梁柱节点连接的半刚性 ,考虑了梁柱间的相对转角关系 ,通过引入梁柱线刚度比修正系数的计算方法 ,推导了有侧移和无侧移半刚接钢框架柱计算长度系数的修正公式 .研究结果表明 :受节点半刚性影响 ,半刚接钢框架柱的计算长度系数比按刚接考虑的计算长度系数增大 ,增大范围约在 6 %～ 9%左右 ;框架柱除底层外 ,其上下两端与横梁的连接基本是半刚接的形式 ,按横梁有侧移考虑 ,柱的计算长度系数比柱两端按照刚性节点计算出的计算长度系数值增大了 9%左右 .由此可见在钢框架的稳定分析和设计中 ,应考虑梁柱节点采用半刚接的连接形式对框架柱的稳定性产生的不利影响     

钢结构框架支撑构件抗侧移效率的探讨

从支撑抗侧移的效率角度，考虑了竖向支撑的承载力和侧移刚度的影响，讨论了钢结构支撑的布置形式及其对框架侧移刚度的影响规律，并对其结构作了分析，以供参考借鉴。     

基础隔震建筑中应用变刚度保护装置的地震反应分析

长周期的地面运动会使隔震建筑物发生类共振而导致隔震支座失稳破坏。在这种情况下,可以利用附加的弹簧改变建筑物的周期,减小隔震层的变形,使之限制在允许的范围内,同时使上部结构的层间剪力不明显增大。按照多质点结构分析模型推导了不发生附加、右侧附加、左侧附加弹簧的运动方程,编制了相应的分析程序。通过对模型实例分析,论证了变刚度保护装置在限制支座大变形中的作用,讨论了在工程设计中如何选取变刚度保护装置的适宜参数。     

钢框架-混凝土剪力墙混合结构的简化计算方法

提出了钢框架——混凝土剪力墙混合结构体系的一种基于连续化方法的简化计算方法，该方法考虑了这种结构中钢框架部分的受力和变形特点，即节点柔性连接(或称半刚性连接)，在本方法中同时也可考虑梁柱二阶效应的影响。明确了在进行钢框架——混凝土剪力墙混合结构的计算分析时，应考虑节点柔性连接和梁柱效应。推导了考虑节点柔性连接和梁柱效应时，钢框架——混凝土剪力墙混合结构中钢框架部分的层间抗侧刚度。该方法物理概念清楚，计算简便，可供设计人员参考。     

Further study on the flexural behaviour of concrete-filled steel tubes

This paper is a further study on the flexural behaviour of concrete-filled steel tubes based on the former work presented by Han [Han LH. Flexural behaviour of concrete-filled steel tubes. Journal of Constructional Steel Research 2004;60(2):313-37]. A total of 36 composite beam specimens filled with self-consolidating concrete (SCC) were tested. The main parameters varied in the tests are: (1) sectional types (circular and square); (2) steel yielding strength (from 235 to 282 MPa); (3) the ratio of tube diameter (or width) to wall thickness, D/t (from 47 to 105), and (4) the ratio of shear span to depth (from 1.25 to 6). Comparisons are made with predicted beam capacities using the existing methods, such as AIJ-1997 [Architectural Institute of Japan (AIJ). Recommendations for design and construction of concrete filled steel tubular structures. 1997], AISC-LRFD-1999 [AISC. Load and resistance factor design specification for structural steel buildings. Chicago: American Institute of Steel Construction, Inc.; 1999], BS5400-1979 [British Standard Institute: BS5400, Part 5, Concrete and composite bridges. 1979], EC4-1994 [Eurocode 4. Design of composite steel and concrete structures, Part 1.1: General rules and rules for buildings (together with United Kingdom National Application Document). DD ENV 1994-1-1:1994. London W1A2BS: British Standards Institution; 1994] and the method proposed by Han [Han LH. Flexural behaviour of concrete-filled steel tubes. Journal of Constructional Steel Research 2004;60(2):313-37].Applied calculation formulae of moment versus curvature curves and the flexural stiffness of concrete-filled steel tubular (CFST) beams are presented, based on the mechanics model of Han [Han LH. Flexural behaviour of concrete-filled steel tubes. Journal of Constructional Steel Research 2004;60(2):313-37]. Comparisons are made with predicted beam flexural stiffness using different methods, such as AIJ-1997, AISC-LRFD-1999, BS5400-1979, EC4-1994 and the method proposed in this paper. Comparisons are also made between the simplified model and the mechanics model, and generally good agreement is achieved.     

Development of moment-rotation model equations for flush end-plate connections

This paper presents the development of Ramberg-Osgood and Three-Parameter Power model prediction equations for the moment-rotation (M-θ) behavior of flush end-plate connections with one row of bolts below tension and compression flanges. A finite element model (FEM) of the connection region along with the connected beam and column is developed for load deformation analyses, which included material, geometric, and contact nonlinearities. The FEM model was verified with test results conducted and reported for flush end-plate connections in the literature during the 1980s. A matrix of test cases was obtained by varying the geometric variables of flush end-plate connections within their practical ranges. The connection M-θ data for these test cases were obtained by FEM analyses, which were then curve fitted to Ramberg-Osgood and Three-Parameter Power model equations to obtain parameters defining these equations. Finally, prediction equations were developed for parameters of the model equations as functions of geometric variables of the flush end-plate connections.     

各柱u(u=kl)不等的带支撑框架的稳定性分析

对于设置了支撑的框架结构 ,并且各柱的u(u =kl)不全相等时的稳定性问题进行了研究 ;对临界荷载和支撑刚度的关系进行了深入分析和探讨 ;分析了荷载不对称的影响。得出一系列结论 ,指导实际设计。     

考虑隅角点承托刚性影响薄壁曲线箱梁的空间计算分析

根据薄壁曲线箱梁受载行为 ,为曲梁力学行为的特点 ,考虑其隅角处承托刚性的影响 ,将曲线箱梁板件视为曲线板梁 ,隅角处承托视为曲线梁元 ,由此提出了考虑隅角承托刚性影响薄壁曲线箱梁空间计算的曲线板梁有限单元法     

外伸端板节点在火灾下的转角-温度关系

通过对外伸端板常温下初始刚度和极限承载力的分析,引入了钢材高温下的材料特性,得出了节点在高温下的初始刚度和极限承载力。假定节点弯矩恒定,按照常温下节点弯矩-转角关系得到了节点的转角-温度公式,并与试验结果进行了比较,吻合较好。