珊瑚骨架在含气冠层下的剥落破坏：一种理想化的爆炸捕鱼模型
Spall Failure of Coral Skeleton beneath Gas-Laden Canopies: An Idealized Blast-Fishing Model
浏览论文内容
中文总结 AI 辅助
针对爆炸捕鱼对珊瑚骨架的破坏，提出理想化模型，揭示含气冠层通过改变冲击阻抗和冲量传递，显著影响骨架板的剥落与压碎距离，并受日循环气体影响。
中文摘要 AI 辅助
在印度尼西亚浅水珊瑚礁中用于捕鱼的简易炸药会击碎珊瑚骨架，然而其造成的损害主要通过经验半径和生态调查来描述。我们构建了一个理想化模型，研究珊瑚冠层内自由气体如何改变此类炸药对骨架板施加的冲击载荷。冠层被视为一种松弛的含气泡混合物，其冲击阻抗由质量和动量守恒得出，而珊瑚礁则被表示为水、冠层、骨架板和冠层的分层柱体，并以法向入射方式受到冲击。我们得到了三个闭式结果。在由空隙率和海水刚度设定的交叉压力之上，冠层对冲击几乎变得透明。通过任何无损耗分层堆栈传递的冲量与冠层无关，因此气体在时间上重新分配脉冲而不改变其总推力。只有当冠层阻抗低于由板厚和脉冲持续时间设定的阈值（该阈值定义了临界厚度）时，板在从其下表面反射后才承受拉力。对于正上方的一公斤炸药，富含气体的冠层使十二厘米板发生剥落的距离增加了三倍以上，同时缩短了其被压碎的距离。光合作用气体的规定日循环使同样的炸药在正午时比夜间更具破坏性。气泡动力学表明，冠层在脉冲内无法达到平衡，因此结果最好被视为上限。
英文摘要
Improvised explosives used for fishing on shallow Indonesian reefs shatter coral skeleton, yet the damage they cause has been described largely through empirical radii and ecological surveys. We formulate an idealized model of how free gas held within a coral canopy modifies the shock loading that such a charge delivers to skeletal plates. The canopy is treated as a relaxed bubbly mixture whose shock impedance follows from the conservation of mass and momentum, and the reef is represented as a layered column of water, canopy, skeletal plate, and canopy struck at normal incidence. Three closed-form results emerge. Above a crossover pressure set by the void fraction and the stiffness of seawater, the canopy becomes nearly transparent to the shock. The impulse transmitted through any lossless layered stack is independent of the canopy, so gas redistributes the pulse in time without changing its total push. A plate carries tension after reflection from its lower face only when the canopy impedance falls below a threshold fixed by the plate thickness and the pulse duration, which defines a critical thickness. For a one-kilogram charge directly overhead, a gas-rich canopy more than triples the standoff at which a twelve-centimeter plate spalls while shortening the standoff at which it is crushed. A prescribed daily cycle of photosynthetic gas makes the same charge markedly more damaging at noon than at night. Bubble dynamics show that the canopy does not reach equilibrium within the pulse, so the results are best read as upper bounds.
发表机构
- Bandung Institute of Technology（万隆理工学院）
- Center for Agrarian Studies, Bandung Institute of Technology（万隆理工学院农业研究中心）
- Headquarters of the Indonesian Armed Forces (Mabes TNI)（印度尼西亚武装部队总部）
- Sumatera Institute of Technology（苏门答腊理工学院）
机构由 AI 辅助整理，请以论文原文为准。
