部分混凝土外包波形钢腹板组合工字梁的抗剪性能试验研究

针对提高负弯矩作用下连续梁的结构特性提出了一种新型的部分混凝土外包波形钢腹板组合工字梁。对这种混凝土外包组合工字梁在对抗荷载下的抗剪性能进行试验分析研究。试验结果显示与普通的工字梁相比,混凝土外包组合工字梁的剪切屈曲因受外包混凝土的限制而有了更好的抗剪强度。由于组合截面的抗剪刚度是基于波形钢腹板和破裂前外包混凝土平均厚度的总和,且其抗剪强度决定了由钢腹板和外包混凝土共享的抗剪强度比。此外,根据试验中的破坏模式和应变分布,提出部分混凝土外包波形钢腹板组合工字梁的预估抗剪强度。试验结果验证了之前分析得出的弹性阶段的抗剪刚度和抗剪比。且之前计算得出的钢腹板与组合梁的抗剪强度也与试验结果一致。通过对比可知文中提到的分析方法可以应用到部分混凝土外包波形钢腹板组合工字梁结构的抗剪刚度预估和抗剪强度设计中去。

Shear Behavior of Partially Encased Composite I-girder with Corrugated Steel Web:Experimental Study

A new type of partially encased composite I-girder with corrugated steel web has been proposed to improve the structural performance of continuous girders under hogging moment. The shear behavior of such partially encased composite I-girders under anti-symmetric loading has been experimentally and analytically investigated. Experimental results show that the partially encased composite girders has superior shear strength compared to steel I-girders, since shear bucking of steel web is restricted by concrete encasement. The shear stiffness of the composite section is based on the total summation of corrugated web and concrete encasement with average thickness before cracking, and the ratio of shear resistance shared by the steel web and the concrete encasement depends on their shear stiffness. In addition, predicted shear strength of the partially encased composite girder with corrugated web is proposed according to the experimental failure mode and strain distribution. The analytical shear stiffness and shear resistance ratio at the elastic stage are verified by experimental results. And the calculated shear strength for steel and composite girders agree well with the experimental results. The comparison shows that the proposed analytical methods can be applied in predicting elastic shear stiffness and design shear strength for such partially encased composite girders with corrugated web.