角钢–双T型纵横梁拼接节点承载特性研究

Study on Bearing Characteristics of the Splicing Joint of Angle Steel-double T-type Beam

拼接节点作为钢桁架结构重要的连接部位,其承载力和刚度是影响钢桁架整体结构安全性和稳定性的重要因素。本文结合大直径钢桁架筒仓施工支撑平台设计提出两种角钢–双T型纵横梁拼接节点的拼接形式,为研究其承载特性,采用静力加载试验和有限单元法,对这两种拼接节点进行研究,分析相同受力和相同约束等条件下带腹板连接板拼接节点和带腹板端板拼接节点的抗弯刚度、极限荷载及破坏模式,以确定较合理的角钢–双T型纵横梁拼接节点的拼接形式,实现大直径钢桁架筒仓施工支撑平台的装配化施工。研究结果表明:相同约束条件下,当荷载达到150 kN时,试验测得带腹板连接板拼接节点的位移比带腹板端板拼接节点的位移小–1.73%,且其抗弯刚度比带腹板端板拼接节点高8.76%。采用有限单元法对带腹板连接板拼接节点和带腹板端板拼接节点进行数值模拟,当荷载达到极限荷载200 kN时,带腹板端板拼接节点塑性变形较大,最后带腹板端板拼接节点先于构件发生剪切破坏;当荷载达到极限荷载220 kN时,带腹板连接板拼接节点塑性变形较大,最后构件先于带腹板连接板拼接节点发生压屈破坏。带腹板连接板的拼接节点更符合"强节点弱构件"的节点设计原则,满足大跨度钢桁架节点拼接要求,其研究成果为钢桁架整体结构性能的研究提供理论依据。

The splicing joint,as an important connection part of steel truss,its bearing capacity and stiffness are important factors on safety and stability of steel truss.Based on the design of large-diameter silo construction support platform,two types of the splicing joint of angle steel-double Ttype beam were proposed.In order to confirm more reasonable splicing form of angle steel-double T-type beam and achieve prefabricated construction of silo construction support platform with large diameter of steel truss,the monotonic load test and the numerical simulation were carried out to study bearing characteristics of the splicing joint and to analyze the bending stiffness,ultimate load and failure mode of two types of the splicing joint under the same load and constraint condition.The results showed that the experimental observations of the splicing joint with web connecting plate is –1.73%,smaller than the splicing joint with web end plate when the load reaches 150 kN under the same constraints,and its bending stiffness is 8.76%,higher than the splicing joint with web end plate.The simulation of the splicing joint with web connecting plate and the splicing joint with web end plate by using the finite element method showed that the plastic deformation of the splicing joint with web end plate is larger when the load reaches the ultimate load of 200 kN,and finally the splicing joint with web connecting plate is buckling failure before member while the plastic deformation of the splicing joint with web connecting plate is larger when the load reaches the ultimate load of 220 kN,and finally the splicing joint with web end plate is shear failure before splicing joint.The splicing joint with web connecting plate is more accorded with the principle of 'strong joint and weak member',satisfying the requirements of splicing joint of the large-span steel truss,and the performance parameters of it can provide theoretical basis for the study of the overall performance of the steel truss.