爆炸冲击波在钢管混凝土柱表面压力分布试验研究及数值模拟

摘要

为了解决爆炸荷载下钢管混凝土柱表面冲击波压力实际分布和数值模拟存在偏差的问题,通过开展钢管混凝土柱爆炸试验,研究冲击波在钢管混凝土柱表面的压力分布,并结合试验建立爆炸荷载下钢管混凝土柱有限元模型,分析不同空气和炸药网格尺寸对冲击波传播及数值分析结果的影响.结果表明：在折合距离为1.1 m/ kg1/3试验条件的爆炸荷载作用下,柱顶与柱底的约束条件良好,柱产生的变形属于弹性变形；考察冲击波对构件的损伤程度,应综合考量峰值压力与正压冲量两者的作用效应；不同空气和炸药网格尺寸对爆炸冲击波的压力峰值及压力时程曲线均有较大影响；数值模拟值与试验实测值的误差随着网格尺寸的减小而降低.综合考察数值分析结果与实测值吻合程度,最终确定：空气和炸药网格尺寸为20 mm,符合折合距离不小于1.1 m/ kg1/3试验条件下的爆炸数值模拟要求.%In order to eliminate the deviation between explosion test and numerical simulation, the pressure distribution of blast wave on the surface of concrete filled steel ( CFST) column had been analyzed by executing the explosion test. And by using FEM procedure and considering the condition of explosion test, a FEM model of CFST column had been established. In order to investigate the influence of the different mesh size of air and explosive on the blast wave propagation and pressure value of blast wave, the numerical simulation with the different mesh size of air and explosive had been executed based on explosion test results. Analysis of research results shows that the constraints of column are in good condition and deformation of column belongs to elastic stage when the scale distance is 1. 1 m/ kg1 / 3 in explosion test. Both peak pressure value and positive impulse value should be considered together in evaluation of damage on column. The different mesh sizes of air and explosive have great impacts on the peak pressure of blast wave and the trend of pressure-time curve. And the results of numerical simulation correspond with the test results well when the mesh density of air and explosive increases. Finally, by examining the accuracy of the numerical results and comparing with the test results, the mesh size of 20 mm is considered to meet the requirements of numerical simulation when the scale distance is not less than 1. 1 m/ kg1 / 3 .