基于饱和响应时间的封闭空间内爆炸载荷等效方法研究

An equivalent calculation method for confined-blast load based on saturated response time

针对舱内爆炸载荷形式复杂、作用时间长、缺乏有效的简化描述方法的问题,首先采用显式动力学计算程序开展了内爆载荷作用下钢板动态响应的数值计算,在与试验结果对比验证的基础上分析了金属板的内爆载荷饱和冲量。通过对216种不同爆炸载荷加载时长与金属板响应关系的分析,提出了内爆炸载荷作用下结构最大变形所对应的饱和时间计算经验公式,并给出了饱和时间的无量纲系数建议值。考虑到内爆载荷初始冲击波的影响,结合爆炸载荷饱和作用时间的规律,提出了封闭空间爆炸载荷的矩形载荷等效方法,对比了18组简化载荷与耦合载荷分别作用下钢板的动力响应,验证了等效方法的有效性。

Due to the complex form and long duration of the load from a confined explosion, it is usually difficult to propose an uniform simplified formula to describe the confined blast load effectively, which can be applied in the predicting the dynamic response of structures. In present paper, the explicit dynamic code Autodyn was employed to predict the response of steel plates under confined blast load numerically. The effectiveness of the numerical method was validated by comparing the numerical and experimental results, and then the characteristic of saturated impulse of steel plate was analyzed. The numerical simulations of 216 plates, which experience different load durations, were conducted. Based on analyzing the relationship between the duration of confined blast load and the subsequent dynamic response of these steel plates, a simplified formula was deduced to determine the saturated time that corresponding to the maximum deformation of plate, and a guide value of the parameter of the dimensionless saturated time was presented. Considering the influence of initial shock wave of confined explosion, combined with the law of saturation action time of explosion load, a rectangular load equivalent method for the confined blast load is proposed. The dynamic response of metal plate under 18 groups of simplified and fully-coupling load is compared, and the effectiveness of the equivalent method is verified.