冷弯薄壁C型钢-混凝土组合梁抗弯性能试验研究及有限元分析

Experimental study and finite element analysis on flexural behavior of cold-formed thin-walled C-shaped steel-concrete composite beam

为探究冷弯薄壁C型钢-混凝土组合梁受弯性能,制作并设计了5个不同断面组合形式的组合梁试件,并对其进行抗弯性能试验研究,分析其承载性能、破坏机理。在试验基础上,通过有限元分析软件ABAQUS对此组合梁进行非线性分析,对其进行参数分析,研究材料、尺寸对组合梁性能的影响。基于试验研究与有限元模拟分析,建立冷弯薄壁C型钢-混凝土组合梁的承载力模型,对其承载力、刚度进行理论分析。结果表明:各组合梁的主要破坏形式均属于延性破坏;采用ABAQUS建立的组合梁有限元模型能较好地模拟冷弯薄壁C型钢-混凝土组合梁的受力过程。随着C型钢屈服强度的增加,极限荷载最高提高56.5%;C型钢厚度每增加1mm,极限荷载平均提高28.5%;截面高度每增加50mm,极限荷载提高20%左右。但是提高混凝土的强度等级对组合梁的承载力影响较小;推导出了适用于此种冷弯薄壁C型钢-混凝土组合梁的抗弯承载力及其刚度计算方法,发现计算结果与试验结果吻合较好。

In order to explore flexural behavior of cold-formed thin-walled C-shaped steel-concrete composite beam,five composite beam specimens with different cross-section combinations were fabricated and designed,and flexural behavior test was carried out to analyze the bearing performance and failure mechanism.On the basis of the test,the nonlinear analysis of the composite beam was carried out by the finite element analysis software ABAQUS,and the parameter analysis was carried out to study the influence of material and size on the performance of the composite beam.Based on experimental research and finite element simulation analysis,the bearing capacity model of cold-formed thin-walled C-shaped steelconcrete composite beam was established,and the bearing capacity and stiffness were theoretically analyzed.The results show that the main failure modes of each composite beam are ductile failure.The finite element model of composite beam established by ABAQUS can better simulate the stress process of cold-formed thin-walled C-shaped steel-concrete composite beam.With the increase of yield strength of C-shaped steel,the ultimate load is increased by 56.5%.For every 1mm increase in the thickness of C-shaped steel,the ultimate load increases by 28.5%on average.For every 50mm increase in the height of the section,the ultimate load increases by about 20%.However,increasing the strength grade of concrete has little effect on the bearing capacity of composite beams.The calculation method of flexural capacity and stiffness of coldformed thin-walled C-shaped steel-concrete composite beams was derived.It is found that the calculation results are in good agreement with the experimental results.