无上弦空腹钢桁架-混凝土板组合楼盖弯剪承载力相关性研究

Study on the Correlation of Flexural Shear Bearing Capacity of Unwinded Hollow Steel Truss and Concrete Slab Composite Floor

本课题组在此之前已设计制作了一榀无上弦空腹钢桁架–混凝土板组合楼盖试件,并对其进行试验分析,同时建立相应的有限元模型对其进一步分析。本文研究内容是基于砣块单元模型,深入研究无上弦空腹钢桁架–混凝土板组合楼盖弯剪承载力相关性。通过对有限元模拟结果与试验结果对比分析,表明本文的ANSYS模型可以较好地模拟无上弦空腹钢桁架–混凝土板组合楼盖的受力与变形。由试验结果有限元与模拟结果可知无上弦空腹钢桁架–混凝土板组合楼盖相对薄弱在弯剪段范围内。基于不同的砣块单元模型,通过对比理论公式与有限元结果,验证抗弯承载力理论公式的准确性,修正了抗剪承载力理论公式。通过大量的有限元模拟结果,拟合出弯–剪承载力相关曲线公式,拟合出的公式可以较准确地计算无上弦空腹桁架组合楼盖的极限承载力。

The research group has designed and produced one specimen of unwinded hollow steel truss and concrete slab composite floor,and carried out experimental analysis on it,as well as set up the corresponding finite element model to further analyze it.In this paper,the correlation between the bending and shear load capacity of the unwinded hollow steel truss and concrete slab composite floor is investigated based on the block unit model.By comparing the finite element simulation results with the test results,it is shown that the ANSYS model in this paper can simulate the stress and deformation of unwound hollow steel truss-concrete slab composite floor.The finite element and simulation results show that the hollow steel truss and concrete slab composite floor without upper chord is relatively weak in the range of flexural shear section.Based on different leadblock element models,the accuracy of the theoretical formula of flexural bearing capacity is verified by comparing the theoretical formula with the finite element results,and the theoretical formula of shear bearing capacity is modified.Through a large number of finite element simulation results,the curve formula of flexural shear bearing capacity is fitted out,and the formula can accurately calculate the ultimate bearing capacity of the composite floor without upper chord.