侧向冲击对钢管混凝土受压承载力影响研究

Lateral Impact Effects on the Compressive Strength of Concrete Filled Steel Tubes

为研究侧向冲击作用对钢管混凝土结构性能的影响,首先基于ABAQUS的非线性有限元静态、动态计算方法,采用实体、壳体单元对钢管混凝土结构受压承载力及受侧向撞击后的变形进行了数值模拟,数值模拟结果与已有试验结果吻合较好。同时为了验证准静态计算方法的有效性,采用静态、准静态计算对受撞击前钢管混凝土结构的受压承载力进行了模拟,模拟结果同样吻合良好,且准静态计算降低了分析难度。最后用准静态计算方法给出了构件受撞击后剩余受压承载力的拟合计算公式。结果表明:撞击速度越大,构件局部变形越大,屈服荷载越低;约束效应系数为影响钢管混凝土构件抗冲击性能的重要因素;拟合计算公式具有一定的参考价值。

To study the compressive performance of concrete filled steel tubes （CFSTs） after lateral impact, the CFSTs were modeled with shell and solid elements. Deflections and compressive strength were analyzed by using ABAQUS/Standard and ABAQUS/Explicit respectively. Simulation results agree well with experimental data. The compressive strengths of CFSTs before impact obtained by the quasi-static method and static method were compared. The results indicate that the quasi-static method can be used to effectively predict the compres- sive strengths of CFSTs with less computational difficulties. Finally, the formula to calculate the residual com- pressive strength of impacted CFSTs was proposed based on the computational results. Calculation results show that with the increase of impact speed, deflection increases but yield stress decreases. Confinement is an impor-tant factor for CFSTs＇impact resistance. The proposed formula can be referred for other engineering projects.