Deng Nianchun, Li Haoxu, Ni Jingyao, Peng Xiuning, Lv Guohua, Chen Zhaotao
College of Civil Engineering and Architecture, Guangxi University, Nanning, 530004, China.
Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning, 530004, China.
Sci Rep. 2024 Sep 2;14(1):20391. doi: 10.1038/s41598-024-68186-0.
Concrete-filled steel tubes (CFSTs) have been increasingly utilized in engineering due to their excellent mechanical properties. Ensuring a solid bond between a steel tube and concrete is essential for optimizing their synergistic effect. This study introduces an internally welded steel bar structure within the inner wall of a steel tube to enhance the bond properties at the connection interface. The influence of various configurations of steel bars welded to the inner surface of the tube on the bond strength is investigated considering the impact of vibration on the load-bearing capacity of the component. This study comprises two groups of specimens, one with vibration and one without vibration, for a total of ten specimens. Each group included CFST members with five distinct internal welded steel bar structures. The experimental results, including load-displacement curves and strain data of the steel tube, were used to assess the impact of the internal welded steel bar configurations on the steel-concrete interface. The sliding process is described by correlating test data with curves and observed phenomena. To comprehensively compare the effects of structural dimensions on the bonding and slipping properties of the welded bars, finite element simulations replicating the experimental conditions were carried out using ABAQUS software, and the simulation results agreed with the experimental observations. The study demonstrated that incorporating internal welded steel bars substantially enhances the bond strength of steel pipe-concrete interfaces. While vibration weakens the bond strength in CFST members, internal welded steel bars mitigate this effect. These findings improve the structural performance of CFST structures and their resilience to external vibrations.
由于其优异的力学性能，钢管混凝土（CFST）在工程中得到了越来越广泛的应用。确保钢管与混凝土之间有牢固的粘结对于优化它们的协同效应至关重要。本研究在钢管内壁引入一种内部焊接钢筋结构，以增强连接界面处的粘结性能。考虑振动对构件承载能力的影响，研究了焊接在钢管内表面的不同钢筋配置对粘结强度的影响。本研究包括两组试件，一组有振动，一组无振动，共十个试件。每组包括具有五种不同内部焊接钢筋结构的钢管混凝土构件。实验结果，包括钢管的荷载-位移曲线和应变数据，用于评估内部焊接钢筋配置对钢-混凝土界面的影响。通过将试验数据与曲线和观察到的现象相关联来描述滑动过程。为了全面比较结构尺寸对焊接钢筋粘结和滑移性能的影响，使用ABAQUS软件进行了模拟实验条件的有限元模拟，模拟结果与实验观察结果一致。研究表明，加入内部焊接钢筋可显著提高钢管-混凝土界面的粘结强度。虽然振动会削弱钢管混凝土构件的粘结强度，但内部焊接钢筋可减轻这种影响。这些发现改善了钢管混凝土结构的结构性能及其对外部振动的恢复能力。
