外包钢管加固RC柱抗冲击试验研究

为改善结构柱抗冲击性能,设计了RC柱和外包钢管加固RC柱在不同轴压比下的抗冲击试验,比较了两种类型柱抗冲击性能差异。试验通过DHR-9401落锤式冲击实验机进行,运用力传感器、高速摄影机和应变片完整记录了冲击力时程曲线、轴力时程曲线、跨中挠度时程曲线和试件特定位置的应变时程曲线。同时运用三种通用动力非线性有限元软件MSC.Marc、ABAQUS和ANSYS/LS-DYNA对冲击试验进行了数值模拟。研究结果表明外包钢管加固RC柱抗冲击性能要明显强于RC柱,证明外包钢管加固RC柱是一种可行的抗冲击加固措施。ABAQUS建立的有限元模型和试验结果吻合最好,MSC.Marc次之,ANSYS/LS-DYNA稍差。但ANSYS/LS-DYNA可较好的模拟RC柱冲击破坏全过程,其他两种软件则较难实现。研究结果可为大型铁路站房抗脱轨列车撞击提供加固措施,并为选取适合的有限元软件进行抗冲击分析提供参考。

EXPERIMENTAL STUDY ON IMPACT RESISTANCE OF REINFORCED CONCERET COLUMNS STRENGTHENED WITH STEEL JACKETS

To improve the impact resistance of structural columns, two series of Reinforced Concrete (RC) columns and RC columns strengthened with steel jackets under different axial compression ratios were designed and experimentally studied. The experiments were performed by using the DHR-9401 drop hammer test machine. The impact resistances of RC columns and RC columns strengthened with steel jackets were compared. The force sensors, high-speed camera and strain gages were used to record data such as the time history curves of impact loads, axial forces, mid-span displacement and strain in specific locations. Three nonlinear dynamic finite element software packages (i.e., MSC.Marc, ABAQUS and ANSYS/LS-DYNA) were adopted to simulate the dynamic behavior of RC columns and RC columns strengthened with steel jackets. Results show that the impact resistances of the RC columns strengthened with steel jackets are significantly stronger than those of the RC columns. Therefore, RC columns strengthened with steel jackets are a feasible impact strengthening measure. The simulated results of ABAQUS were the best agreeing with experiment results, followed by MSC.Marc and ANSYS/LS-DYNA. ANSYS/LS-DYNA was found to well simulate the entire impact failure process of RC columns, which was difficult to achieve by the other two software packages. The outcomes can assist in providing impact resistance measures for the strengthening design of large railway stations subjected to derailed trains, and offering reference for selecting suitable finite element software package for impact resistance analysis.