工字形钢柱的爆炸作用分布特征与计算研究

Distribution features and calculation of blast loading for I-shaped steel columns subjected to explosion

为研究工字形钢柱上的爆炸荷载特征,明确在不同爆炸条件下工字形钢柱的破坏形式,通过数值计算和试验数据相结合,在三种不同爆炸类型条件下,对钢柱不同位置测点的冲击波曲线形式进行分析,并对钢柱不同翼缘的爆炸荷载水平及竖向分布形式进行总结,给出工字形钢柱上爆炸作用的确定方法。研究结果表明:当爆炸作用沿钢柱强轴时,荷载在翼缘宽度上可按均匀分布,而随近、中、远爆炸类型的变化,荷载沿钢柱竖向分别呈双曲线、梯形和矩形分布特征,而荷载峰值可按TM5-855中试验数据确定;当爆炸作用沿钢柱弱轴时,荷载在腹板上可按均匀分布,而在翼缘上呈三角形分布特征,荷载峰值可按TM5-855中试验数据值乘以相应的放大系数得到;爆炸荷载对钢柱响应形式影响显著,随着爆炸距离的增大,钢柱由局部破坏向整体破坏转变。

To investigate features of blast loading and its failure mode for I-shaped steel columns under different explosion types,numerical calculations and tests were conducted. The time histories of overpressure for different measured points were analyzed in detail. The spatial distribution of blast loading for a steel column was evaluated. The results showed that when explosion along strong axis,the load on the flange width can be assumed to be a uniform distribution;with changes of near,medium and far explosion types,loads along the vertical direction of the steel column are hyperbolic,trapezoidal and rectangular distributions,respectively; the peak loads can be determined according to test data of TM5-855; when explosion along weak axis,loads on the web can be assumed to be a uniform distribution while they are a triangular distribution on the flange; the peak loads can be determined according to the product of test data of TM5-855 and the corresponding amplification factor; the response of the steel column is significantly affected by the features of blast loading; with increase in explosion distance,local damages change into the overall failure for the steel column.