悬臂钢管混凝土构件在横向冲击荷载下承载性能有限元分析

摘要

The dynamic behavior of concrete-filled steel tube(CFST) specimens with one end fixed and the other end free are analyzed under lateral impact load by theoretical and finite element methods. The ultimate moment is de- termined by 'Unified Theory', and the deflection is computed using theoretical formula. The results obtained by soft- ware ANSYS/LS-DYNA are correct and reasonable compared with those of theoretical formula. The stress, strain and acceleration time-history curves on important position are analyzed based on the results. The results demonstrate: while the restriction parameter, material strength and size are constant, the final deflection is proportional to impact energy; the impact energy is transferred from the free end to the fixed end, and finally the plastic hinge is formed in the fixed end; the CFST has relatively higher ability of absorbing energy and deformation, and the typical plastic characteristic of the stress and strain are observed.%通过理论计算和有限元方法分析了悬臂钢管混凝土构件在横向冲击荷载下的力学性能,根据“统一理论”确定构件的极限弯矩，利用理论公式计算构件的挠度,采用有限元软件ANSYS／LS-DYNA模拟相应工况,并与理论结果比较，得到了构件重点部位的应力、应变和加速度时程,结果表明，当套箍系数、材料强度和尺寸一定时，构件最终挠度与冲击能量成正比；冲击能量从自由端向固定端传递，固定端截面逐步进入屈服，最终形成塑性铰构件成为机动结构，丧失承载力；钢管混凝土构件具有较好的耗能和变形能力。应力、应变呈现典型弹塑性材料自特征．