Abstract
In order to establish safe, inexpensive, and effective laboratory experimental technique for simulating the behavior of shock waves generated by large-scale explosion, an experimental investigation of shock waves propagation created by the explosion of a micro-charge, Silver-azide with 10-mg of mass, inside the 50th-scaled model with complicated closed-cell structure is reported. Comparing the relationship between overpressure and scaled-distance by the micro-charge with by TNT, we have evaluated that the scaled-law is also established for the micro-charge explosion as same as for large-scale explosion. The TNT equivalence ratio for the micro-charge has been estimated to be 0.31. Visualization of shock waves propagation inside the model have been carried out using double-exposure holographic interferometry equipped with a pair of 1-m-diameter parabolic mirror. Both overpressure measurements over walls inside the model and visualization results indicate that overpressure inside closed-space values more than 10 times as large as at open-space. The fact that muti-refrection of shock waves inside the model gives high-frequent overload to the structure has been shown.
大規模爆発で発生する爆風および衝撃波の挙動を実験室内で安全,低費用かつ効率的に模擬する実験手法の確立を目的とし,密閉複雑構造を有する縮尺模型内部で微小爆薬(アジ化銀,10mg)による爆発で発生させた衝撃波の挙動について報告する。まず,爆風圧測定実験から微小爆薬による爆風圧が大量の爆薬の爆風圧と相似性があることを見出し,微少量アジ化銀のTNT換算係数0.31を得た。この結果から,密閉複雑構造建築物の1/50縮小模型を製作し,有効径1mの放物面鏡を備えた二重露光ホログラフィ干渉計法を用いて,微小爆薬起爆による衝撃波の模型内伝播様態を可視化計測した。可視化結果と模型内壁での過剰圧履歴から,密閉構造を有する建物内では,通常の10倍程度の圧力上昇が発生すること,衝撃波の複雑な反射により壁面に繰り返し負荷が加わることなどを明らかにした。
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