钢梁-钢筋混凝土柱梁柱边节点抗剪性能分析

本文采用ANSYS有限元软件分析了8个不同节点构造的"梁贯通式"钢筋混凝土柱-钢梁(RCS)边节点的抗剪性能,详细分析了RCS节点柱上端相对侧移及其组成、侧向荷载-剪应变、节点区各组成元件的抗剪承载力、节点剪力-变形曲线、钢腹板应力的发展过程、试件破坏时的应力应变分布等。结果表明,RCS节点变形是三维空间变形,内、外混凝土之间存在相对转动;RCS节点总变形由剪切变形和承压变形组成,即使发生节点剪切破坏,承压变形也占有较大比例;RCS节点抗剪由三部分组成:钢腹板、内混凝土和外混凝土,如设有钢柱面板,还应包括钢柱面板的抗剪承载力;在节点区总变形小于2%时,节点的抗剪承载力随节点总变形的增大而增大,在节点区总变形大于2%时,节点的抗剪承载力随节点总变形的增大而基本保持不变;试件破坏时,钢腹板大部分已屈服,屈服区为柱截面高度的80%,内、外混凝土有明显的斜压带存在。这些信息对进一步研究RCS节点抗剪机理和抗剪模型具有重要意义。

Shear Behavior of Exterior RCS Beam-Column Connections

Static behavior of eight through-beam-type exterior RC column-to-steel beam(RCS)connections with different joint details is analyzed by the finite element software ANSYS.In this paper,the story drift and its components,lateral load-shear strain relationship,the individual contribution of different elements to the joint shear capacity,joint shear force-deformation relationship,stress developing process of the steel web,stress and strain distribution at the last converged sub-step is investigated.The study shows that RCS joint deformation is three-dimensional and there exists a relative rotation between the inner and outer concrete.The total joint deformation is the sum of joint distortion and joint bearing deformation,which accounts for a large amount of the total joint deformation even in the case of join shear failure.Three components are found to contribute to the shear strength of RCS joints:steel web,inner concrete,and outer concrete.If steel cover plates are used,their contribution should be included.When the total joint deformation is smaller than 2%,the joint shear capacity increases along with this deformation increase,after that,the joint shear strength remains unchanged.When specimens fail,a large part of steel web has yielded and the width of yielded zone equals to 80% of the column depth,and there is an apparent diagonal strut in both inner and outer concrete.The informations provided in this paper are very important for further investigating the shear mechanism and shear model of RCS joints.