密闭空间内爆炸缩比相似模型研究

以相似理论为基础,对密闭空间内爆炸毁伤参数进行量纲分析,建立密闭空间内爆炸相似模型,用LS-DYNA进行原模型装药递增直至结构破坏计算，并以结构产生裂纹的临界装药量进行缩比系数分别为0.8，0.6，0.4，0.2，0.1的缩比模型仿真计算。结果表明,结构尺寸不变而药量变化时壁面的冲击波服从相似规律；反射超压服从以受单、双及三面墙影响分开考虑的相似规律；冲量由于受结构破损影响不服从相似规律；缩比系数不小于0.1时缩比模型与原模型壁面的冲击波超压、比例脉冲宽度及比例冲量服从相似规律，缩比模型冲击波超压、比例脉冲宽度及比例冲量与原模型最大相对误差分别为3.3%、4.96%、5.1%；随缩比系数的减小，结构壁面的冲击波超压及冲量呈现出离散分布特性，相似程度有所降低。在研究的缩比系数范围内，可利用缩比模型试验结果预测原模型内爆炸毁伤效应。

Study on scale similarity model for internal explosion in closed field

The damage parameters of internal explosion in closed field are analyzed by using the dimension analysis principle, and the scale similarity model for internal explosion in closed field is established based on the similarity theory in this paper. The internal explosion of the original model under incremental charges manner until structural damage and the scale model under critical charge of structure cracks with different scale coefficients values of 0.8, 0.6, 0.4, 0.2 and 0.1 respectively are simulated by LS-DYNA code. The results show that, when the structure size stays constant but the explosive quality is changed, the arrival time of shock wave on the wall obey to similarity law, and the shockwave overpressure obey to similarity law which considered separately and affected by one wall, two walls and three walls respectively, but the impulse is not subject to similarity law due to the influence of structural damage. The shockwave overpressure, scale pulse width and scale impulse on the wall between scale model and original model obey to similarity law when the scale coefficient is no less than 0.1, and the maximum relative error of shockwave overpressure, scale pulse width and scale impulse between scale model and original model are less than 3.3%, 4.96% and 5.1% respectively. As the scale coefficients decrease, the shockwave overpressure, scale pulse width and scale impulse on the wall show a discrete distribution and the similarity degree decreases gradually. So if the scale coefficients are within the scope of this study it is feasible to predict the damage effect of original model under internal explosion using the scale mode experiment.