氢气在实际应用中存在着许多负压场景,确定负压工况下的燃爆参数是对氢气进行科学评估和有效防控的首要前提。采用高精度配气及爆炸压力采集系统研究氢气在负压场景下的燃爆特性,明确氢气的爆炸上限、爆炸下限、临界爆炸压力、最大爆炸...氢气在实际应用中存在着许多负压场景,确定负压工况下的燃爆参数是对氢气进行科学评估和有效防控的首要前提。采用高精度配气及爆炸压力采集系统研究氢气在负压场景下的燃爆特性,明确氢气的爆炸上限、爆炸下限、临界爆炸压力、最大爆炸压力、最大爆炸升压比等燃爆参数;并通过Python中的Matplotlib等软件库对试验数据进行拟合,分析压力对氢气燃爆参数的影响。结果表明:在室温、空气条件下,初始压力从100 k Pa降至3.5 k Pa的过程中,爆炸范围不断缩小,特别是从初始压力低于10 k Pa开始,爆炸范围缩小速度明显增加,该现象与分子间距受压力影响的变化趋势存在强关联;当初始压力低至3.72 k Pa时,爆炸上、下限重合在12.58%体积分数的位置,该压力称为临界爆炸压力,低于该压力时体系将失去爆炸性;一般认为最大爆炸压力通常在理论当量体积分数29.6%附近取得,试验发现此规律仅适用于初始压力大≥5 k Pa的场景,当初始压力<5 k Pa时,理论当量体积分数将随着压力的减小而发生改变,逐渐偏离至体积分数10%~15%;最大爆炸升压比会随着初始压力的减小而降低,从常规的7.30降低至4.63,特别是在初始压力<5 k Pa的体系中,该比值大幅降低。展开更多
The proposed prediction model for estimating the maximum rebound ratio was applied to a field explosion test, Mandai test in Singapore. The estimated possible maximum peak particle velocities(PPVs) were compared with ...The proposed prediction model for estimating the maximum rebound ratio was applied to a field explosion test, Mandai test in Singapore. The estimated possible maximum peak particle velocities(PPVs) were compared with the field records. Three of the four available field-recorded PPVs lie exactly below the estimated possible maximum values as expected, while the fourth available field-recorded PPV lies close to and a bit higher than the estimated maximum possible PPV. The comparison results show that the predicted PPVs from the proposed prediction model for the maximum rebound ratio match the field-recorded PPVs better than those from two empirical formulae. The very good agreement between the estimated and field-recorded values validates the proposed prediction model for estimating PPV in a rock mass with a set of joints due to application of a two dimensional compressional wave at the boundary of a tunnel or a borehole.展开更多
负泊松比结构由于优异的力学特性,逐渐被广泛应用于抗爆炸、抗侵彻等领域。提出了一种基于负泊松比结构的复合结构,从抗侵彻、抗爆炸两个角度设计了三个主要功能层,运用有限元仿真方法探究了异型陶瓷负泊松比复合结构在爆炸环境和弹丸...负泊松比结构由于优异的力学特性,逐渐被广泛应用于抗爆炸、抗侵彻等领域。提出了一种基于负泊松比结构的复合结构,从抗侵彻、抗爆炸两个角度设计了三个主要功能层,运用有限元仿真方法探究了异型陶瓷负泊松比复合结构在爆炸环境和弹丸侵彻下的响应特征,分析了防护机理并设计了参数优化方案,研究了陶瓷层最低厚度、负泊松比结构纵向蜂窝数、内凹六边形凹角、钢板厚度、聚脲层厚度等参数对结构抗爆抗弹性能的影响。通过能量吸收率(Specific Energy Absorption,SEA)、侵彻深度、中心点位移等指标评估不同参数组对应复合结构的防护能力。结果表明,陶瓷层最低厚度是影响结构抗侵彻能力的最大因素,聚脲层厚度和负泊松比结构纵向蜂窝数是影响结构抗爆能力的较大因素。在降低面密度的同时调整各参数,获得了最优抗爆抗侵彻的复合结构设计方案,实现了低面密度与高强防护的结合。研究提供了工程防护增强设计的新思路,助力推进了防护工程轻质化、模块化发展。展开更多
文摘氢气在实际应用中存在着许多负压场景,确定负压工况下的燃爆参数是对氢气进行科学评估和有效防控的首要前提。采用高精度配气及爆炸压力采集系统研究氢气在负压场景下的燃爆特性,明确氢气的爆炸上限、爆炸下限、临界爆炸压力、最大爆炸压力、最大爆炸升压比等燃爆参数;并通过Python中的Matplotlib等软件库对试验数据进行拟合,分析压力对氢气燃爆参数的影响。结果表明:在室温、空气条件下,初始压力从100 k Pa降至3.5 k Pa的过程中,爆炸范围不断缩小,特别是从初始压力低于10 k Pa开始,爆炸范围缩小速度明显增加,该现象与分子间距受压力影响的变化趋势存在强关联;当初始压力低至3.72 k Pa时,爆炸上、下限重合在12.58%体积分数的位置,该压力称为临界爆炸压力,低于该压力时体系将失去爆炸性;一般认为最大爆炸压力通常在理论当量体积分数29.6%附近取得,试验发现此规律仅适用于初始压力大≥5 k Pa的场景,当初始压力<5 k Pa时,理论当量体积分数将随着压力的减小而发生改变,逐渐偏离至体积分数10%~15%;最大爆炸升压比会随着初始压力的减小而降低,从常规的7.30降低至4.63,特别是在初始压力<5 k Pa的体系中,该比值大幅降低。
基金Project(50278057) supported by the National Natural Science Foundation of Chinaproject(2002CB412703) supported by the Major State Basic Research Development Program of China
文摘The proposed prediction model for estimating the maximum rebound ratio was applied to a field explosion test, Mandai test in Singapore. The estimated possible maximum peak particle velocities(PPVs) were compared with the field records. Three of the four available field-recorded PPVs lie exactly below the estimated possible maximum values as expected, while the fourth available field-recorded PPV lies close to and a bit higher than the estimated maximum possible PPV. The comparison results show that the predicted PPVs from the proposed prediction model for the maximum rebound ratio match the field-recorded PPVs better than those from two empirical formulae. The very good agreement between the estimated and field-recorded values validates the proposed prediction model for estimating PPV in a rock mass with a set of joints due to application of a two dimensional compressional wave at the boundary of a tunnel or a borehole.
文摘负泊松比结构由于优异的力学特性,逐渐被广泛应用于抗爆炸、抗侵彻等领域。提出了一种基于负泊松比结构的复合结构,从抗侵彻、抗爆炸两个角度设计了三个主要功能层,运用有限元仿真方法探究了异型陶瓷负泊松比复合结构在爆炸环境和弹丸侵彻下的响应特征,分析了防护机理并设计了参数优化方案,研究了陶瓷层最低厚度、负泊松比结构纵向蜂窝数、内凹六边形凹角、钢板厚度、聚脲层厚度等参数对结构抗爆抗弹性能的影响。通过能量吸收率(Specific Energy Absorption,SEA)、侵彻深度、中心点位移等指标评估不同参数组对应复合结构的防护能力。结果表明,陶瓷层最低厚度是影响结构抗侵彻能力的最大因素,聚脲层厚度和负泊松比结构纵向蜂窝数是影响结构抗爆能力的较大因素。在降低面密度的同时调整各参数,获得了最优抗爆抗侵彻的复合结构设计方案,实现了低面密度与高强防护的结合。研究提供了工程防护增强设计的新思路,助力推进了防护工程轻质化、模块化发展。
