钢-混凝土组合梁受扭性能的试验及分析

为研究新型外包钢-混凝土组合梁的抗扭性能,完成了2根不同配箍率的组合梁纯扭试验和3根不同弯扭比组合梁复合受扭试验.测得了试件的扭矩-扭率曲线,钢筋扭矩-应变曲线,组合梁U形钢侧面、底面的应变分布及沿板宽方向的混凝土的应变分布.试验结果表明:组合梁扭转变形符合三阶段变形规律,翼板混凝土破坏与普通钢筋混凝土构件受扭破坏相似.在试验基础上,通过受扭性能的弹塑性理论分析以及变角空间桁架模型的极限承载力的分析计算,得到组合梁开裂扭矩以及极限扭矩的计算公式,与试验结果进行对比后发现两者吻合较好.

Torsion experiment and analysis on steel-encased concrete composite beams

In order to study the torsion behavior of steel-encased concrete composite beams,experiments were conducted on two specimens with varied stir-up ratios subjected to pure torsion and on three specimens with varied ratios of torsion to bending moment.The torsion ratio,torsion-strain relationship,strain distribution for steel and concrete,and the strain distribution along slab width direction were all mea-sured.Experiments showed that the torsions accord with three stage deformation rule and the rupture of concrete board conforms with common reinforced concrete.On the basis of experiment,according to the elastic and plastic theory and analysis on the bearing capacity by using spatial truss model with variable angle,cracking torque and ultimate torque of composite beams are obtained.The results are in good agreement with measured ones.