近爆作用下中空夹层超高性能钢管混凝土柱的抗爆性能

Anti-Blast Performance of Ultra-High Performance Concrete-Filled Double Steel Tubes under Close-in Blast Loading

为研究中空夹层超高性能钢管混凝土(Ultra-high performance concrete-filled double skin steel tubes,UHPCFDST)柱在近爆载荷作用下的抗爆性能,建立了TNT炸药-UHPCFDST柱-空气三维有限元模型,采用ALE多物质流固耦合算法分析了UHPCFDST柱在近爆作用下的损伤机理、能量吸收特性和影响参数,计算结果表明:UHPCFDST柱在近爆作用下的典型破坏模式为钢管的塑性变形和混凝土芯柱的凹陷破坏,且混凝土芯柱的损伤过程可以分为3个阶段;与填充普通混凝土柱相比,UHPCFDST柱具有优异的抗爆性能;在一定范围内,减小截面空心率可以有效提升UHPCFDST柱的抗爆性能;增加内外钢管厚度均可提升UHPCFDST柱的抗爆性能,但增加外层钢管厚度时提升效果更显著;有无轴压对UHPCFDST柱的变形有较大影响,在一定范围内增加轴压比有利于抵抗整体变形,但同时局部变形增大,当轴压比较大时,UHPCFDST柱在近爆载荷和轴向载荷作用下失去承载能力。

In order to study the explosion resistance of ultra-high performance concrete-filled double skin steel tubes(UHPCFDST)under near-explosive loads,a three-dimensional finite element model of TNT explosives-UHPCFDST columns-air was established.The ALE multi-material fluid-solid coupling algorithm is used to analyze the damage mechanism,energy absorption characteristics and influence parameters of UHPCFDST columns under near-explosion.The calculation results show that the typical failure modes of UHPCFDST columns under near-explosion are plastic deformation and the collapse of the concrete core pillar.The damage process of the concrete core pillar can be divided into three stages.Compared with the ordinary concrete column,the UHPCFDST column has superior anti-blast performance;within a certain range,reducing the cross-section hollow ratio can effectively improve the explosion resistance of UHPCFDST columns;increasing the thickness of inner and outer steel pipes,particularly for the inner pipe,can increase the explosion resistance of UHPCFDST columns.The presence of axial pressure has a great influence on the deformation of the UHPCFDST column.The increase of axial pressure ratio,within a certain range is beneficial to resisting the overall deformation.As the axial pressure continues to increase,local deformation increases and the UHPCFDST column would lose its strength under the combined effects of the near-blast and the axial loads.