冲击波和预制破片复合作用下H型钢柱损伤效应分析

Damage Effect Analysis of H-Section Steel Columns Subjected to Synergistic Effects of Blast and Prefabricated Fragments

为探究H型钢柱在近距爆炸冲击波和预制破片复合作用下的抗爆性能,基于非线性有限元软件ANSYS/LSDYNA,通过在圆柱形TNT炸药柱身外贴预制破片来模拟爆炸产生的冲击波和破片对钢柱的损伤破坏.分析了冲击波载荷、破片群载荷及复合载荷作用下H型钢柱动态响应的差异.同时,通过参数化分析方法,探究了在冲击波和预制破片复合作用下轴压比、钢材强度、长细比和截面类型等因素对H型钢柱损伤效应的影响规律.结果表明,近爆作用下,冲击波和预制破片的复合载荷作用具有叠加增强效应,复合载荷作用大于单一载荷作用效果的线性叠加.在钢柱抗爆设计中,应控制其所承受的轴向压力,钢材强度等级为Q235时,轴压比不宜大于0.4.应合理选择钢材强度等级,不要盲目选择高强钢材.通过改变柱高来改变长细比对钢柱破坏影响不大.圆管型截面钢柱的抗爆能力最好,H型截面次之,箱形截面最差.

In order to investigate the anti-blast performance of H-section steel columns at blast and prefabricated fragments, the damage effect of the combined blast and fragments loads on the H-section steel column is simulated by arranging the prefabricated fragments around the cylindrical TNT based on the nonlinear finite element software ANSYS / LS-DYNA. The difference of dynamic response of H-section steel columns at blast load, fragments load, and combined blast and fragments load is analyzed. Meanwhile, the influence of axial compression ratio, steel strength, slenderness ratio, and cross section type on the dynamic response of the steel column at combined blast and fragments load is investigated by using the parametric analysis method. The research indicates that the combined effect of blast and prefabricated fragments under adjacent explosion has a superposition enhancement effect and the combined load is bigger than the linear superposition of single load effect. In the anti-blast design of steel columns, the value of the axial pressure should be controlled, and when the steel strength grade is Q235 the axial compression ratio should not be bigger than 0.4. It is reasonable to choose steel strength instead of blindly choosing high-strength steel. By changing the column height to change the slenderness has little effect on the steel column. Tubular cross-section steel column has the best anti- blast ability, followed by H-section and box section.