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对5根采用蝶形连接件的不同构造形式的筑巢轻钢龙骨体系桁架梁进行承载力试验和有限元分析,研究筑巢轻钢桁架梁在竖向荷载作用下的受力特点、破坏模式、极限承载力及影响桁架梁抗弯刚度和极限承载力的主要因素。结果表明:桁架梁主要发生上弦端部或跨中的受弯或压弯破坏;减小第1个连接件距端部的距离或采用斜撑的方式会使桁架梁的破坏位置发生改变,但对承载力影响不大;增大上弦管的截面面积可以明显提高梁的极限承载力,但梁的抗弯刚度增长幅度不大;采用节点刚性假定模拟分析挠度误差较大,而考虑节点半刚性模型分析的结果与试验值更为接近;桁架梁主要由其跨中挠度控制设计,在正常使用阶段,桁架梁的承载力只为极限承载力的33%～45%。
The bearing capacity and the finite element analysis of five truss girders with different configurations of the nesting light steel keel system with butterfly connection were carried out to study the stress characteristics and failure mode of the light steel truss girder under vertical load. , Ultimate bearing capacity and the main factors affecting the flexural rigidity and ultimate bearing capacity of truss girders. The results show that the main bending or bending of the truss girder occurs at the ends or in the midspan of the truss girder. Decreasing the distance of the first connecting member from the end or using the braces will change the breaking position of the truss girder. However, But the bending stiffness of the beam increases little. The rigidity deflection of the node is assumed to be large when the simulation is carried out, while the semi-rigidity of the joint is considered The results of model analysis are closer to the experimental values. The truss girder is mainly designed by the mid-span deflection control. During normal use, the truss girder’s bearing capacity is only 33% ~ 45% of the ultimate bearing capacity.