@techreport{oai:jaxa.repo.nii.ac.jp:00041461,
 author = {熊倉, 郁夫 and 峯岸, 正勝 and 岩崎, 和夫 and Kumakura, Ikuo and Minegishi, Masakatsu and Iwasaki, Kazuo},
 month = {Oct},
 note = {4 Oct. 2000, 4 Oct. 2000, 客室の耐衝撃性向上対策として、胴体構造などの衝撃吸収特性を考慮した構造設計が期待される。本報告では、中型または大型機の胴体下部構造を想定した構造モデルの検討を行い、縮小模型の垂直落下試験および解析を行った事例を紹介した。対象とした構造形態の1つのモデルは、床下構造の衝撃変形特性を、床剛性を剛とし、床高さをパラメータとして把握することである。第2のモデルは、床剛性を考慮し、座席位置や胴体上部の慣性質量を集中質量で近似して床剛性や床ビームを支持するストラットの影響を調べることである。構造衝撃解析には陰解法の非線形衝撃解コードであるLS-DYNA3Dを用いた。機軸を水平にし自由落下させ、スチール製のベースプレートに衝突させた。胴体底面が接触後に、最大変位および最大加速度レベルに達するまでの所要時間は、床高さが大きいほど遅くなることを確かめた。床位置の変位については実験値との一致はかなり良いが、加速度については改善の余地がある。ストラットの有無の影響は少なかった。第2の床剛性を考慮したモデルによる解析を現在進めているが、適切な床剛性選択の可能性が示唆された。, As a measure for improving the impact-resistance of the cabin, structural design of fuselage with impact-absorbing characteristics is expected to be effective. In this report, case-studies are introduced, in which the structural models of the lower portion of the fuselage of a middle-sized or large-sized aircraft were investigated. A vertical drop-test of reduced-scale models and analysis of the test-results were conducted. The first group of structure models for testing was selected to grasp the changes in impact deformation characteristics of the lower structure with fixed high rigidity of the floor and with floor-height as the variable parameters. The second model group was selected to grasp the effects of the floor-rigidity and the struts that support floor-beams evaluating the change of floor-rigidity, on the premise that the inertial mass of the seat-positioning and the upper part of the fuselage can be represented by a concentrated mass. For the structural impact analysis, LS-DYNA3D, a non-linear impact solution code of the implicit analysis method was applied. The models were held with the fuselage axis horizontal and then subjected to a free drop, to crash on a steel base plate. The time-lapse needed to reach the maximum displacement and acceleration after the contact of the bottom surface of the fuselage with the base plate was confirmed to get longer with the increase in the height of the fuselage floor. The analyzed displacement of the floor position was found in good agreement with the experimental values, while with respect to the acceleration there is much room for improvement. The effect of absence or presence of the struts was found to be small. As for the second model used to grasp effects of floor rigidity, analysis is now under progress. Interim results suggest the possibility of identifying an optimum floor-rigidity., 資料番号: AA0028639010, レポート番号: NAL SP-50},
 title = {航空機胴体構造の落下衝撃特性と解析手法について},
 year = {2000}
}