共查询到19条相似文献,搜索用时 156 毫秒
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为了给坑道防护工程防爆炸空气冲击波的设计与研究提供一定的参考依据,收集整理了国内外常用的计算坑道口外爆炸产生的坑道内爆炸空气冲击波传播参数的计算方法,对其进行了比较和分析后给出了能够较好描述冲击波传播规律的计算方法。采用ANSYS AUTODYN有限元软件对某坑道比例模型试验进行了数值模拟,将模拟结果与坑道模型试验数据进行了比较,说明采用ANSYS AUTODYN有限元软件进行爆炸冲击波问题的数值模拟是可行的。 相似文献
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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。
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为研究坑道内爆炸冲击波相似律问题,进行了不同药量坑道堵口爆炸实验,并利用ANSYS/LSDYNA软件对原型坑道与模型坑道爆炸冲击波进行数值计算。结果表明:与自由大气中不同,同一坑道内不同药量爆炸产生的冲击波不符合爆炸相似律;若原型坑道与模型坑道几何相似,装药量之比为几何相似比的三次方,则原型坑道与模型坑道内爆炸冲击波符合爆炸相似律;坑道内爆炸冲击波数值模拟时,若原型坑道与模型坑道网格尺寸符合相应的几何相似比,则冲击波计算结果满足相似律,当坑道截面网格密度为1675~2977时可以达到计算精度要求。 相似文献
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强爆炸冲击波对坑道内部的人员、设备和结构等均能产生巨大的毁伤破坏作用,因此如何消减冲击波强度的防护技术成为研究热点。本文以模型坑道和实际坑道为平台,系统开展了不同数量的集中置水(袋装水)和不同长度均匀置水(均布水)的消波效应试验,对试验结果进行了分析对比;并结合试验现象对水的消波机理进行了初步探讨。结果表明:无论集中置水还是均匀置水都具有显著的消波性能;直坑道内爆炸近区两者的消波效果相近,而在爆炸远区均匀置水的要高出约10%;较复杂的穿廊结构坑道比直通坑道具有更加明显的消波效果;增加置水量能提高超压衰减率,在相同位置增加相同数量水(15kg)时,即集中置水每增加1袋和均匀置水每增长1m时,超压衰减率分别提高约2%和5%;总体来说,均匀设置的消波效果更优于集中设置。 相似文献
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Accidental blast wave generation and propagation in the surroundings poses severe threats for people and property. The prediction of overpressure maxima and its change with time at specified distances can lead to useful conclusions in quantitative risk analysis applications. In this paper, the use of a computational fluid dynamics (CFD) code CFX-5.6 on dense explosive detonation events is described. The work deals with the three-dimensional simulation of overpressure wave propagation generated by the detonation of a dense explosive within a small-scale branched tunnel. It also aids at validating the code against published experimental data as well as to study the way that the resulting shock wave propagates in a confined space configuration. Predicted overpressure histories were plotted and compared versus experimental measurements showing a reasonably good agreement. Overpressure maxima and corresponding times were found close to the measured ones confirming that CFDs may constitute a useful tool in explosion hazard assessment procedures. Moreover, it was found that blast wave propagates preserving supersonic speed along the tunnel accompanied by high overpressure levels, and indicating that space confinement favors the formation and maintenance of a shock rather than a weak pressure wave. 相似文献
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考虑炸药起爆、冲击波传播、冲击波与结构的相互作用以及结构的动态响应等复杂过程,基于Lagrange-Euler耦合算法,建立了水底隧道水下爆炸的全耦合数值仿真模型。通过与爆炸试验结果进行对比,验证了数值模型的可靠性;研究了水下爆炸冲击荷载作用下的水底隧道的毁伤破坏过程、空间分布规律及破坏模式。结果表明:水底隧道的破坏模式不仅与隧道自身的动力特性有关,还取决于起爆距离及炸药当量等;隧道的破坏模式为局部冲切或剥落破坏、弯曲破坏伴随着局部剥落破坏以及整体弯曲破坏。 相似文献
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考虑炸药起爆、冲击波传播、冲击波与结构的相互作用以及结构的动态响应等复杂过程,基于Lagrange-Euler耦合算法,建立了水底隧道水下爆炸的全耦合数值仿真模型。通过与爆炸试验结果进行对比,验证了数值模型的可靠性;研究了水下爆炸冲击荷载作用下的水底隧道的毁伤破坏过程、空间分布规律及破坏模式。结果表明:水底隧道的破坏模式不仅与隧道自身的动力特性有关,还取决于起爆距离及炸药当量等;隧道的破坏模式为局部冲切或剥落破坏、弯曲破坏伴随着局部剥落破坏以及整体弯曲破坏。 相似文献
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Zhenbi Su Wen Peng Zhaoyan Zhang George Gogos Reed Skaggs Bryan Cheeseman 《International Journal of Impact Engineering》2008
This paper proposes a novel blast wave mitigation device, consisting of a piston–cylinder assembly. A shock wave is induced inside the device when it is subject to a blast wave. The shock wave propagates inside the device and is reflected repeatedly. The physical processes within the blast wave mitigation device are simulated numerically. Numerical predictions are in excellent agreement with analytical solutions for special cases of the investigated problem that are available in the literature. The peak pressure on the base of the device caused by the blast wave is studied using a number of design parameters. The numerical simulation shows that, although the transmitted impulse remains practically unchanged, the peak pressure of the blast wave can be reduced by as much as 98%, or even higher, depending on the design parameters chosen. 相似文献
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城市复杂环境中爆炸波的传播规律与超压荷载 总被引:1,自引:1,他引:0
该文利用LS-DYNA软件,采用ALE方法,对城市复杂环境中爆炸波的传播规律与超压荷载进行了数值模拟和分析。通过对两建筑物模型中爆炸波传播的数值模拟及其与单建筑物模型的对比分析,结果表明两建筑物模型中爆炸波由于在两建筑物之间多次反射而被增强,因此在计算建筑物所受到的爆炸波超压荷载时必须考虑相邻建筑物的影响。通过对一典型T型街道中爆炸波传播的数值模拟及其与简单环境的对比分析,结果表明在城市街道中爆炸波受到地面和周边建筑物的多次反射而增强,且在一定高宽比范围内,街道越窄、周边建筑物越高,爆炸波超压荷载的增大系数越大,因此在分析城市复杂环境中爆炸波的传播规律和超压荷载时必须考虑周边建筑物的影响。从而为制定城市大型及重要建筑的防爆措施提供依据。 相似文献
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Experimental results and numerical simulations have demonstrated that a protective barrier can effectively reduce blast load and, therefore, protect structures from an external explosion. However, there are no formulae in the open literature that can be used to estimate the blast loads on a structure behind a barrier. In this paper, pseudo-analytical formulae based on numerical results are derived to estimate the reflected pressure-time history on a rigid wall behind a protective barrier. Numerical simulations of blast wave propagation are carried out to estimate the peak reflected pressure and the impulse on a rigid wall behind a blast barrier. The shock wave front arrival time and positive phase duration are extracted from the numerical results. Pseudo-analytical formulae, which are derived from the best-fitted curves of the numerical results, are suggested. These formulae can be used with those given in TM5-1300 or other methods for blast pressure estimation in the no-barrier case, to estimate pressure-time histories at various building locations behind a protective barrier. 相似文献