钢管混凝土平缀管格构柱换算长细比计算方法.docVIP

钢管混凝土平缀管格构柱换算长细比计算方法 　　摘要：分析了现有钢管混凝土平缀管格构柱换算长细比计算方法的假定条件和计算式，并将各方法计算的极限承载力与试验结果进行对比；以格构柱剪切柔度理论为基础，对钢管混凝土平缀管格构柱各变形项与总剪切变形量的比值进行分析，指出现有换算长细比计算方法的不合理之处。借鉴钢管混凝土（斜缀条）格构柱换算长细比乘法算法的计算思路，在剪切系数计算式中采用考虑节点构造参数影响的剪切柔度简化计算式，拟合得到放大系数与剪切系数的关系式。结果表明：采用所提出的换算长细比计算方法及GB 50923―2013中稳定系数计算方法得到的计算结果与试验结果吻合良好，证明该方法简单、实用且具有足够的精度。 　　关键词：钢管混凝土；平缀管格构柱；换算长细比；剪切系数 　　中图分类号：TU375.3文献标志码：A 　　Abstract： The assumptions and formulas of existing calculation methods for equivalent slenderness ratio of concretefilled steel tube（CFST）battened columns were analyzed. The calculated ultimate load capacity results were compared with test results. Based on the shear deformation theory of battened columns， each shear deformation item and its proportion in the whole deformation of CFST battened columns were analyzed. The unreasonableness in the existing method was pointed out. According to the calculation method of multiplication algorithm for equivalent slenderness ratio of CFST battened columns，the simplified formula of shear flexibility parameter was introduced to shear factor formula. The relationship between the amplification coefficient and shear flexibility parameter was obtained through the fitting analysis. The results show that the ultimate load carrying capacity can be calculated by adopting the calculation method for equivalent slenderness ratio and stability coefficient formula in GB 50923―2013. The calculated ultimate load carrying capacity agrees well with the test result， which indicates that the proposed method on the equivalent slenderness ratio of CFST battened columns is simple， practical and enough accurate. 　　Key words： concretefilled steel tube； battened column； equivalent slenderness ratio； shear flexibility parameter 　　0引言 　　本文研究的钢管混凝土平缀管格构柱是指由钢管混凝土柱肢和空钢管平缀管通过相贯线焊接形成的受力构件，它在土木工程中有着较广泛的应用，如拱肋[13]、高墩[46]等。由于缀件在结构发生横向挠曲时的变形较大，稳定计算时剪切变形的影响应该计入，常用的做法是在稳定系数计算时采用换算长细比。 　　与钢缀板柱相比，钢管混凝土平缀管格构柱中平缀管的抗弯惯性矩较小且构件较短，受力性能有所不同。现有的计算方法多沿用钢缀板柱的计算方法[79]，且相关的研究不多，目前仅见文献[10]进行了24根试件的试验研究，研究结果表明，现