钢管混凝土梁在侧向冲击荷载作用下动力响应的试验研究和数值模拟

Experimental study and numerical simulation of the dynamic response of concrete filled steel tubes under lateral impact load

钢管混凝土构件和其他材料的结构构件一样,在役期间不可避免地要受到意外撞击,为了了解其破坏过程进而为结构设计提供理论依据,对套箍系数分别为1、1.15和1.9的两端简支钢管混凝土梁在不同侧向冲击能作用下的动力响应进行试验研究和仿真分析。动载试验在DHR-9401落锤式冲击实验机上进行,试验过程中通过力传感器和应变片记录冲击力时程曲线和试件特定位置的应变时程曲线,试验结束后测量试件整个跨度范围内的侧向位移,获得试件残余变形模态。利用ANSYS/LS-DYNA软件,采用PLASTIC-KINEMATIC和SOIL-CONCRETE材料模型分别模拟钢管和其核心混凝土材料,对试验过程进行数值模拟,得到的跨中挠度和冲击力时程曲线与试验结果非常一致,进而对试件的应变变化情况进行深入的研究,给出钢管混凝土试件的临界破坏状态。研究结果表明,套箍系数是影响构件临界破坏能量的一个最重要的因素,临界破坏能是套箍系数的二次函数。

Experiment and numerical simulation were conducted to study the dynamic response of simply supported beams of concrete filled steel tubes with different casing hoop steel coefficients. The experiments were carried out on the DHR-9401 drop hammer test machine, and the residual deformation modes and the time history curves of impact loads were recorded. The concrete-filled steel tube under impact load was analyzed by using the LS-DYNA software, and the results were in the fair agreement with the experimental ones, with some phenomena that cannot be measured in the experiment were simulated, and the critical destroy state was defined. The results indicate that the effect of the casing hoop steel coefficients on the critical destruction energy is obvious and that the critical destruction energy is a quadratic function of the casing hoop steel coefficients.