爆炸波信号识别及其动力学过程的实验研究

通过测试到的不耦合装药加载条件下混凝土中产生的径向爆炸波信号分析,识别和分离了信号中的爆炸冲击波、应力波及爆生气体膨胀作用,并就各自作用时间、大小、衰减规律及爆后损伤开展了定量研究。结果表明:在同一测点处同时受到爆炸冲击波、应力波及爆生气体的共同作用,作用时间分别为3.5,3.3和16.6μs;爆炸冲击波表现为压应力,峰值在1000 MPa以上;应力波表现为拉压作用,爆生气体膨胀表现为持续的拉应力或压应力的准静态作用。爆炸冲击波应力峰值随距离呈非线性快速衰减,应力波和爆生气体作用正负应力峰值随距离衰减缓慢,混凝土中爆炸波作用分区与凝聚炸药爆轰结构的压力分布有关。爆后混凝土的损伤实验表明:爆炸除形成了通自由面的7条裂纹外,在炮孔周围形成了半径为12.5 cm的损伤区,且损伤阈值Dcri=0.2,与理论计算一致。

Recognition of blasting wave signals and dynamics of explosion process

The explosion shock waves,stress waves and detonation gas action from the explosive waves are separated and recognized by analyzing the radial blasting wave signals tested in concrete under the decoupling charge,and their parameters are quantitatively studied.The results show that the three kinds of blasting wave act on the measuring points of concrete at the same time.The time of their individual contribution is about 3.5,3.3 and 16.6 μs,respectively.The stress of the shock wave shows itself in the compressive way,whose magnitude of the peak value stress reaches above 1000 MPa.And the stress of the stress wave shows itself in the tensile and compressive way.The detonation gas action shows itself as lasting tensile stress or compressive stress.Then the damage tests on the concrete after explosion show that the explosion has formed a damage zone with a radius of 12.5 cm around the borehole and produced 7 pieces of cracks on the surface of concrete.The damage threshold value Dcri is 0.2.The radius of the damaged zone of concrete is greater than the depth of the damaged zone.