@article{oai:jaxa.repo.nii.ac.jp:00031457,
 author = {河田, 幸三 and 橋本, 彰三 and KAWATA, K. and HASHIMOTO, S.},
 issue = {2},
 journal = {東京大学宇宙航空研究所報告},
 month = {Apr},
 note = {弾性波による動的応力集中を高速光弾性で解析し,その静的と異なる挙動を明かにした.光弾性材料としてポリウレタン,弾性波の撮影には1万p/sの高速度コマどりカメラを用い,鮮明な等色線図を得ることができた.試片は切欠,又は段付部をもつ短冊状で,負荷としては,継続時間の短いパルスの使用を避け,試片下端に定速度引張りを加えて得られる,波頭の後にρcv(ρ:密度,c:弾性波速度,v:引張り速度)の高さの一定応力値が長時間続く弾性波を用いた.この波頭および初期のplateauが切欠を通過するときの集中応力の縞次数をρcvの縞次数で割って得られる動的応力集中係数は,静的のそれの約0.5～0.6倍であることが知られた.この値は,切欠部をあらい近似として断面積不連続部と考え,ここを通過する弾性波の理論を適用した計算結果と比較すると,段付棒についてはそのまま一致し,局部的切欠棒についてはその初期の値と一致する., Dynamic stress concentrations due to elastic waves are analyzed by high speed photoelasticity and some differences between dynamic and static stress distributions are clarified. Specimens such as long struts with shoulders or notches are loaded dynamically by an elastic wave behind the front of which a plateau of constant stress pcv (p: density, c: elastic wave velocity, v: tensile velocity) of long duration exists. Such elastic wave is caused in the strut specimen by pulling its lower end in constant velocity, with a falling weight large enough attached to there. Dynamic isochromatic patterns caused in polyurethane rubber specimens are recorded with a 'HIMAC 16 H' high speed camera (framing speed: 10,000 pictures per second). The distinctions of the patterns are nearly equal to those of ordinary static patterns. It is known that dynamic stress concentration factors, that is, max. fringe order in passage of the wave front and the plateau of pcv, divided by the fringe order corresponding to the height of the plateau, are about 0.5～0.6 times static ones, for the specimen dimensions of the present work. An approximate theory of dynamic stress concentration factor is derived, considering notches as discontinuities in cross sectional area of strut, as a rough approximation. The above mentioned theoretical consideration may explain the values of dynamic stress concentration factors obtained experimentally., 資料番号: SA0124339000},
 pages = {69--103},
 title = {<論文>長い定応力部をもつ弾性波による動的応力集中の解析について},
 volume = {1},
 year = {1965}
}