空间管桁架混凝土组合梁受弯性能试验研究

Experimental study on bending performances of spatial pipe truss concrete composite beams

设计制作了空间管桁架混凝土组合梁,通过组合梁的试验研究,得到了荷载-跨中挠度关系曲线、组合梁沿梁长方向的挠度曲线以及组合梁跨中截面应变沿梁高变化曲线,对比有限元分析结果表明:组合梁纵向应变沿梁高近似符合平截面假定;在整个受力阶段钢管桁架和混凝土翼板共同受力性能良好;组合梁在荷载作用下的抗变形能力较强;管桁架节点受力复杂,节点承载力是结构承载力的控制因素;有限元模型可以真实地反映实际结构的受弯承载力和挠度发展的情况。

The bending performances of spatial pipe truss concrete composite beams are design. Based on the experimental study of composite beams, we got the load-midspan deflection curve, composite beams along the beam length direction of the deflection curve and composite beams across the cross section curves of high strain along the beam. Comparison of finite element analysis showed that the composite beams of longitudinal strain along the beam high of beam approximation accord with flat section assumption. It performs well in the entire stress stage steel truss and concrete of wing plate stress. The composite beams are stronger in resistance to de-formation under the action of load. The bearing capacity of loading is complex, and the pipe truss node is the control factor of structure bearing capacity. The finite element model can truly reflect the flexural bearing ca-pacity and deflection.