新型内衬组合波形钢腹板的剪切行为

Shear Behavior of Corrugated Steel Webs with New Encasement

针对内衬混凝土约束波形钢腹板褶皱效应致使支承区预应力导入效率降低的不足,提出了一种采用滑槽-栓钉式连接的新型内衬.为探索设置新型内衬对波形钢腹板褶皱效应和剪切性能的影响,设计了分别采用纯波形钢腹板和新型内衬组合波形钢腹板的工字钢梁试件,通过本构关系、焊接残余应力和几何初始缺陷幅值的敏感性分析,建立了数值模拟方案,并将数值模拟结果与文献试验结果对比,以验证模拟方案的合理性.随后对比研究了新型内衬组合波形钢腹板和纯波形钢腹板的轴向刚度、应变分布、屈曲模态和抗剪强度.结果表明:所采用的数值模拟方案能准确模拟结构的屈曲模态、极限承载力和应变分布.设置新型内衬后,结构的轴向刚度基本不变;纯波形钢腹板和新型内衬组合波形钢腹板的正应变和剪应变分布基本一致,且正应变均服从拟平截面假定,剪应变沿腹板高度均匀分布;设置新型内衬前后腹板屈曲模态均为交互屈曲模式;设置新型内衬后,结构的极限承载能力提高约23%,破坏时的竖向挠度增大约71%;设置新型内衬提升了腹板的面外刚度,约束了早期面外位移的开展速度,在加载后期,新型内衬的存在限制了面外位移的开展程度.

To address the problem of the reduced efficiency of prestress introduction in the supporting area due to the wrinkle effect of corrugated steel webs restrained by concrete lining,a new lining with chute-stud connection encasement is proposed.In order to explore the influence of new lining on the wrinkle effect and shear performance of corrugated steel webs,I-steel beam specimens with pure corrugated webs and new lining composite corrugated webs are designed.A numerical simulation scheme is established through the sensitivity analysis of the constitutive relationship,welding residual stress,and geometric initial defect amplitude.The numerical simulation results are compared with the experimental results in the literature to verify the rationality of the simulation scheme.Then,the axial stiffness,strain distribution,buckling mode,and shear strength of the newly lined composite corrugated web and the pure corrugated web are compared.The results show that the numerical simulation scheme can accurately simulate the buckling mode,ultimate bearing capacity,and strain distribution of the structure.After the new lining is installed,the axial stiffness of the beam structure with composite corrugated webs is basically unchanged.The distribution of the normal strain and the shear strain of the pure corrugated web and the newly lined composite corrugated web is basically the same,and the normal strain obeys the quasi plane section assumption,and the shear strain uniformly distributes along the height of the web.The buckling modes of the front and rear webs of the new liner are both interactive buckling modes.After the new lining is installed,the ultimate bearing capacity of the structure is increased by about 23%,and the vertical deflection at failure is increased by about 71%.The new lining improves the out-of-plane stiffness of the web and restricts the development speed of out-of-plane displacement in the early stage.In the late stage of loading,the existence of the new lining limits the development degree of out-ofplane displacement.