等效球药包迭加模型的应力计算分析

Calculation and Analysis on Stress Superposition Model of Equivalent Spherical Charge

结合Starfield单元球迭加原理,认为单元球药包的质量和个数是影响条形药包近场应力特征的主要因素。在分析条形药包的现有理论研究方法的基础上,引入条形药包的长径比参数,构建了单孔装药量的爆破应力迭加公式。通过具体的算例得出：当条形药包的装药直径取4 cm时,计算出的最优长径比范围为10-12,装药量（TNT）为544-654 g。通过迭加公式的理论模型与其数值模型的应力场分布特征进行对比分析,发现迭加球药包应力场在径向方向始终呈柱面波形式向外扩散,并同时存在“端部效应”;其理论值和模拟值的相对误差控制在20%以内,验证了应力迭加公式的计算方法是可行的,为单孔装药引起的应力计算和应力场分析提供了一个简易的数学模型。

Combined with Starfield superposition principle, it is obtained that the quality and number of the equivalent element spherical charge are the main factors affecting the near-filed stress characteristics induced by explosion of linear charge. Based on analysis of current theoretical,result on linear charge, blasting stress superposition formula of the single explosive charge is deduced with the introduction of linear charge parameters of length-diameter ratio. When the diameter of linear charge is 4 cm, the calculated optimal range of length-diameter ratio is 10 - 12 and the charge of TNT is 544 - 654 g according to the proposed superposition formula. Through comparative analysis on the stress-distribution characteristics of superposition formula with theoretical model and FEA model, it is found that the stress field of equivalent spherical charge keeps spreading outward in the form of cylindrical waves in the radial direction and the end effect comes in to being at the same time. The relative error value of theoretical value and simulated value are below 20%, therefore, the proposed method with the superposition formula of equivalent element- spherical charge is proved to be feasible. A simple formula is provided for calculation and analysis of stress induced by single-hole charge in this work.