建筑抗爆研究中超压的分布特征及确定方法

爆炸超压是描述爆炸荷载的重要指标，不同方法的超压计算结果具有较高的离散性。通过分析试验数据图表拟合确定入射超压与反射超压关系的反射系数计算式，搜集转化得到大量爆炸超压理论计算公式与爆炸试验数据，从而对爆炸超压在不同比例距离下的分布特征进行分析。研究结果表明：当比例距离小于0.5 m/kg^1/3时，爆炸超压概率密度服从指数分布；当比例距离大于0.5 m/kg^1/3时，爆炸超压概率密度服从正态分布。当比例距离小于0.5 m/kg^1/3时，爆炸超压变异系数达最大值1，比例距离在1.5~6.0 m/kg^1/3之间时，变异系数较小，在0.13~0.2 m/kg^1/3之间；反射超压变异系数较入射超压略大。依据不同比例距离下爆炸超压分布期望数据，拟合得到爆炸超压的计算公式与具有95%保证率条件下的爆炸超压分布范围计算公式。

Distribution characteristic and determination of overpressure for blast resistant study of buildings

Explosion overpressure is an important indicator to describe blast load.And the results obtained by different methods have high discreteness.Based on this, the reflection coefficient formula of the relationship between incident overpressure and reflection overpressure is determined firstly by analyzing the experimental data chart fitting.Then a large number of theoretical calculation formulas and explosion test data were collected and transformed to analyze the distribution characteristics of explosion overpressure at different proportional distances.The results show that the probability density of explosion overpressure obeys exponential distribution when the scaled distance less than 0.5 m/kg^1/3.And obeys normal distribution when the scaled distance greater than 0.5 m/kg^1/3.The variation coefficient reaches the maximum value 1 when the scaled distance less than 0.5 m/kg^1/3.While variation coefficient is in the range of 0.13 to 0.2 when the scaled distance within the range of 1.5 m/kg^1/3 to 6 m/kg^1/3.The variation coefficient of reflect overpressure is a little bigger than that of incident overpressure.According to the expected data of explosion overpressure distribution at different proportional distances, the calculation formula of explosion overpressure and the calculation formula of explosion overpressure distribution range with 95% guarantee rate are obtained by fitting.