基于MCFT方钢管混凝土柱受剪承载力计算模型

为准确预测方钢管混凝土柱(square concrete filled steel tube,SCFST)受剪承载力,建立了基于修正压力场理论(modified compression field theory,MCFT)的SCFST受剪承载力计算模型.该模型通过力的平衡和变形协调考虑压弯剪耦合作用,结合对SCFST受剪承载力机制的分析,推导出了计算SCFST受剪承载力的一般公式.注意到SCFST在试验中出现了两种不同的剪切破坏模式,模型分别给出了相应的破坏判别条件.利用SCFST受剪承载力计算模型对收集到的17根试件进行计算,所得结果与试验值吻合较好.研究发现,SCFST受剪承载力计算模型不仅可以计算SCFST在压弯剪共同作用下的受剪承载力,而且可以对SCFST的破坏模式进行判断,结果可信,可用于SCFST受剪承载力计算.

Shear Capacity of Square Concrete Filled Steel Tube Columns Based on Modified Compression Field Theory

To accurately predict the shear capacity of square concrete filled steel tube (SCFST) columns, a theoretic model was established based on modified compression field theory. In this model, compatibility and equilibrium relationships were taken to consider the axial-flexure-shear interaction, and a general formula of shear capacity of SCFST was deduced by dissecting shear mechanism. Due to two different failure modes observed in previous tests, two different failure criterions were given respectively. The proposed model was applied to the 17 existing column specimens, which predicted well the shear capacities of the test specimens. The results show that the proposed model not only can be utilized to evaluate shear capacity of SCFST subjected to axial force, flexural moment, and shear force, but also can be employed to verdict different failure modes. The calculation results of the proposed model are credible, and the model is effective.