EPS泡沫在径向不耦合爆破中吸能效应数值仿真

基于大型非线性显式动力有限元程序LS-DYNA对初始密度分别为12.0,21.0,27.0kg.m-3的聚苯乙烯(EPS)泡沫作充填材料的径向不耦合爆破进行数值模拟.分析了在嵌入不同密度EPS泡沫下混凝土爆破中的损伤以及孔壁周围压力、速度和加速度的分布与衰减规律,并与水不耦合以及空气不耦合爆破的数值模拟结果进行了对比,发现EPS泡沫可以有效地吸收爆炸能量,减小孔壁周围混凝土的损伤区范围;其次,EPS泡沫初始密度ρ0对混凝土损伤影响较大,随着ρ0的增大,EPS泡沫吸能减振功效变得相对不明显,通过调整泡沫初始密度或改变装药不耦合系数Kd可取得相近的爆破效果;最后,为了在取得较好爆破效果的同时降低爆破成本建议EPS泡沫填充时Kd取值在2.0以内.

Numerical Simulation on Energy-absorption of EPS Geofoam in Radical Uncoupled Blast

Based on the large-scale finite element code LS-DYNA with explicit integration,the numerical simulations on radical uncoupled blast filled with expanded polystyrene(EPS) foam of three initial densities(12.0,21.0,27.0 kg·m-3) were performed.The distribution and evolution laws of concrete damage,hydrostatic pressure,velocity and acceleration of particles around the blasthole were analyzed.In addition,the comparisons between the radical foam uncoupled blast with the radical air and water uncoupled cases were also made.The result shows that EPS foam absorbs blast energy effectively,as well as reducing damaged zone around the blasthole.Then,the initial density of EPS foam ρ0 has a relatively great impact on the concrete’s damage distribution.With the increase of ρ0,EPS foam has less capacity of energy absorption and vibration attenuation.By the adjustment of the decoupling coefficient Kd and ρ0 can achieve similar blast result.Finally,in order to achieve better result with a lower blast cost,the value of Kd is proposed to be less than 2.0 when using EPS foam as filling material.The conclusions obtained offer good reference for engineering blast practice.