圆形钢管混凝土叠合构件抗冲击性能试验研究

Experimental behavior of circular concrete-encased concrete-filled steel tubes under lateral impact

开展了钢管混凝土叠合试件落锤冲击系列试验,研究了横向落锤冲击荷载下圆形钢管混凝土叠合试件的破坏模态、整体变形和局部变形特点,将钢管混凝土叠合试件与钢管混凝土试件、钢筋混凝土试件在横向冲击荷载下的破坏模态进行对比。分析了冲击力、轴力和跨中挠度时程曲线的特征,研究了冲击能量、轴力和钢管厚度等参数对圆形钢管混凝土叠合试件在横向冲击荷载作用下力学性能的影响规律。研究结果表明,管外钢筋混凝土部件与核心钢管混凝土部件能够协调互补、共同工作,叠合试件表现出良好的抗冲击性能。在该试验的参数范围内,随着冲击能量的增加,冲击力峰值、跨中挠度峰值、冲击持续时间增加;预加轴压力试件的冲击力峰值较大、冲击力平台值较小;钢管厚度较大试件的冲击力峰值和冲击力平台值较大,跨中挠度峰值较小、冲击持续时间较短。

A series of tests were conducted for concrete-encased concrete-filled steel tubes under lateral drop hammer impact, and their failure modes, overall and local deformation patterns were analyzed based on the experimental study. Failure modes of concrete-encased concrete-filled steel tubes were compared with those of concrete-filled steel tubes and reinforced concrete specimens. Furthermore, characteristics of time-history curves for impact force, axial force and mid- span deflection were studied ; effects of those parameters, such as impact energy, axial force and thickness of steel tube, on the mechanical behavior of circular concrete-encased concrete-filled steel tubes under lateral impact were also investigated. Results indicate that the outer reinforced concrete component can work coordinately with the inner concrete- filled steel tube component, and test specimens exhibit good impact resistance performance. Within the experimental parameter scope, the peak value of impact force, the peak value of mid-span deflection and the impact duration increase with the increase of impact energy. For specimens with pre-applied axial load, the peak value of impact force is higher, while the plateau value of impact force is lower. For specimens with larger thickness of steel tube, both the peak value and the plateau value of impact force is higher, the peak value of mid-span deflection is lower, and the impact duration is shorter.