切缝药包不耦合装药爆破损伤破坏的分形研究

为研究不同不耦合系数下切缝药包的爆后损伤破坏特征,以有机玻璃为试验材料,对不耦合系数1.33、1.67、2.00、2.33、2.67的切缝药包爆破损伤破坏进行分析。基于分形理论中计盒维数的原理,编写MATLAB程序分别计算5种不耦合系数下切缝药包在切缝方向以及垂直切缝方向爆生裂纹的分形维数。对爆后裂纹长度以及数量进行统计分析,结果表明:①在试验选取的不耦合系数范围内,切缝方向裂纹的分形维数显著大于垂直切缝方向的分形维数,切缝药包对于爆生裂纹扩展方向的控制具有明显效果;②在试验选取的不耦合系数中存在最佳不耦合系数1.67,在该不耦合系数下切缝方向爆生裂纹分形维数达到最大值,裂纹长度最大,爆破损伤破坏的定向控制效果最佳;③在不耦合系数大于1.67后,随着切缝药包不耦合系数的逐渐增大,切缝方向的裂纹扩展长度逐渐变短。

Fractal research on blasting damage of slotted cartridge decoupling charge blasting

In order to study the post-explosion damage characteristics of slotted cartridge under different decoupling coefficients,using plexiglass as test material,analysis blasting damage of slotted cartridge with decoupling coefficients 1.33, 1.67, 2.00, 2.33, 2.67. Based on the principle of box counting dimension in fractal theory, compile MATLAB program to calculate the fractal dimensions of the blasting cracks in the cutting slot and the vertical cutting direction under the five kinds of decoupling coefficients.Statistical analysis of crack length and number after explosion, the result shows: (1) Within the range of decoupling coefficients selected in the test,The fractal dimension of the crack in the slit direction is significantly larger than the fractal dimension of the vertical slit direction,the slotted cartridge has obvious effect on the control of the crack propagation direction. (2)Among the decoupled coefficients selected in the test, there is an optimal decoupled coefficient of 1.67, Under this decoupling factor, the fractal dimension of the crack in the kerf direction reaches the maximum, the crack length is the largest, and the directional control effect of blast damage is the best. (3) After the decoupling coefficient is greater than 1.67, as the decoupling coefficient of the slit-sealing pack gradually increases, the crack propagation length in the slit direction gradually becomes shorter.