爆炸荷载作用下基于抗剪承载力的钢柱失效准则

为实现爆炸荷载作用下钢柱快速损伤评估及失效分析,作者分别基于壳单元的精细化模型和梁-柱纤维模型,研究了爆炸荷载作用下钢柱的动态响应;通过位移、剩余竖向承载力和钢柱最大剪力指标,对钢柱进行损伤评估和失效分析.在钢柱剩余承载力基础上提出了基于抗剪承载力的钢柱失效破坏准则,并通过数值模拟对其进行验证.结果表明:基于抗剪承载力的钢柱失效准则能较为准确地预测钢柱在爆炸荷载作用的剪切破坏及由此导致的钢柱剩余承载能力的丧失;梁-柱纤维模型可用于钢柱的损伤失效分析,比精细化模型的计算效率高,但分析结果偏于安全.

Failure Criterion of Steel Columns Under Blast Load Based on Maximum Shear Resistance

In order to achieve the rapid damage degree assessment and failure analysis of steel columns under blast loading,a failure criterion was proposed based on the maximum shear resistance of the steel column. Firstly,dynamic responses of steel columns under blast load were analyzed through numerical simulations with shell elements and beam-column fiber elements. And then damage degree assessment and failure analysis of the steel column were carried out and compared regarding to different possible failure criteria,such as the horizontal displacement,the post-blast residual axial load carrying capacity and the maximum shear force of the steel column. Based on the comparison results,the maximum shear resistance based failure criterion was proposed and finally extensively validated. The results show that the proposed failure criterion could accurately predict the shear failure of the steel column under blast load,as well as the decrease of the axial load carrying capacity. Thus,the proposed failure criterion can be used with beam-column fiber element for damage degree assessment and failure analysis of steel columns,which could achieve good and conservative results with high computational efficiency.