Attenuation characteristics of shock waves interacting with open and closed foams
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摘要: 对冲击波与开式、闭式泡沫作用及其在空气中的传播特性开展实验研究,探讨不同结构的泡沫材料对冲击波衰减的力学特征。通过定量分析泡沫材料对冲击波的超压峰值、正冲量的损失,分析冲击波入射、反射、透射的正冲量。实验结果表明, 泡沫材料对冲击波的衰减体现在对冲击波的反射衰减等方面,其中开式泡沫对冲击波的衰减效果比闭式泡沫稍好,且它们衰减冲击波的具体力学过程也不尽相同。Abstract: Experiments were carried out to explore the mechanical properties of the attenuation of shock waves respectively interacted with wooded plates, open and closed cellular foams. Based on the experimental data, the peak overpressure and positive impulse loss of shock waves were quantitatively analyzed as well as the positive impulses of the incidence, reflection and transmission shock waves. The experimental results show that the attenuation capacity of foams to shock waves is mainly due to the shock wave reflection and energy dissipation inside the foam microstructure. And the mechanical phenomena of open foam to shock wave are not fully consistent with those of closed foam, while the attenuation capacity of open foam to shock wave is more effective than that of closed foam.
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表 1 自由场中冲击波的测试结果
Table 1. Experimental results of shock wave propagating in air
实验编号 p/kPa Δt/ms I/(Pa·s) No.1 No.2 No.1 No.2 No.1 No.2 1 78.4 48.3 0.210 0.510 9.11 7.71 2 78.8 50.3 0.220 0.525 9.24 8.00 3 75.7 53.7 0.225 0.495 9.13 7.30 平均 77.6 50.8 0.218 0.510 9.16 7.67 表 2 开式泡沫材料实验结果
Table 2. Experimental results of shock wave interacting with open foam
实验编号 pin/kPa ptran/kPa pref/kPa Φp/% ηp/% Iin/(Pa·s) Itran/(Pa·s) Iref/(Pa·s) ΨI/% θI/% 7 80.7 11.3 45.0 86.0 55.8 9.16 2.52 6.28 72.5 68.6 8 80.5 10.5 29.6 87.0 36.8 9.16 2.65 4.88 71.1 53.3 9 81.8 11.0 45.1 86.6 55.1 9.16 2.64 4.42 71.2 48.3 平均 81.0 10.9 39.9 86.5 49.3 9.16 2.60 5.19 71.6 56.7 表 3 闭式泡沫材料实验结果
Table 3. Experimental results of shock wave interacting with closed foam
实验编号 pin/kPa ptran/kPa pref/kPa Φp/% ηp/% Iin/(Pa·s) Itran/(Pa·s) Iref/(Pa·s) ΨI/% θI/% 10 107.6 20.1 45.2 81.3 42.0 9.16 3.01 6.42 67.1 70.1 11 98.2 19.9 42.8 79.7 43.6 9.16 3.09 5.60 65.9 61.1 12 103.9 19.4 48.8 81.3 47.0 9.16 2.75 5.83 70.0 82.3 平均 103.2 19.8 45.6 80.8 44.2 9.16 2.95 5.95 67.8 65.0 表 4 冲击波超压值的衰减参数
Table 4. Attenuation parameters of three materials to shock wave overpressure
材料 pin/kPa ptran/kPa Φp/% λp 空气介质 77.6 50.8 34.5 1.00 开式泡沫 81.0 10.9 86.5 2.51 闭式泡沫 103.2 19.8 80.8 2.34 表 5 冲击波正冲量值的衰减参数
Table 5. Attenuation parameters of three materials to shock wave positive impulse
材料 Iin/(Pa·s) Itran/(Pa·s) ΨI/% λI 空气 9.16 7.67 16.3 1.00 开式泡沫 9.16 2.60 71.6 4.39 闭式泡沫 9.16 2.95 67.8 4.16 -
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