摘 要:炸药在坑道内爆炸将产生沿坑道传播的空气冲击波,冲击波与坑道壁相互作用,使得坑道内冲击波的传播规律明显不同于自由大气中冲击波的传播规律。使用有限元计算软件LS-DYNA对已有的坑道试验进行了数值模拟,通过数值模拟结果与试验结果数据比较,验证了有限元计算中所使用的计算模型和参数取值的合理性。利用数值模拟的计算结果,使用量纲分析理论,拟合了距离爆炸中心点一定距离处爆炸冲击波超压峰值的计算公式,并与试验结果进行对比,分析了该公式的适用性,为坑道中爆炸冲击波的传播规律研究提供了参考。
Abstract: An explosion inside the tunnels would generate blast wave which transmits through the longitudinal tunnels. Because of the close-in effects of the explosion and the reflection by the confining tunnel structure, blast wave propagation inside the tunnels is distinct from which in air. When the explosion happens inside tunnel structure, the peak overpressure is higher than which the explosion happens in air. The duration of the blast wave also becomes longer. With the help of the numerical simulation finite element software LS-DYNA, a three-dimensional nonlinear dynamic simulation analysis for a experiment of the explosion inside the tunnels has been made. LS-DYNA is a fully integrated analysis program specifically designed for nonlinear dynamics and large strains problems. Compared with the experiment results, the simulation results have made the material parameters of numerical simulation model available. Making use of the model and the same material parameters, many results have been adopted by calculating the model under variety for different TNT explosion dynamites .Then the method of dimensional analysis has been used for the simulation results. As the explosion blast wave overpressures are the governing factor in the tunnels response, a formula has been suggested for calculating the blast wave peak overpressures at a certain distance from the detonation center point inside the tunnels by using the dimensional analysis theory. Compared the results computed by the formula with experiment results which had been done before board and in, the formula has been proved very applicable at some instance. The research may be helpful to rapidly estimate the tunnel internal explosion effects on the structure.