有限板中の中央2重U字切欠きから発生したき裂の引張りにおける応力拡大係数について

摘要

In general, cracks are initiated from stress concentration sites: notch, hole and so on. The stress intensity factors of the cracks which are initiated from typical notches were computed numerically in the earlier studies. Then, as for the stress intensity factor of the short crack from the notch root, some simple formulae were proposed by some researchers. However, there are few data on the stress intensity factors of the cracks from the complex notches. In this paper, the stress intensity factors of the cracks from a center double U-shaped notch in a finite plate under a tensile stress were computed by the body force method. Then, the influences of the double notch and the plate edges on the stress intensity factors were examined, and the stress intensity factors were expressed with the simple formulae approximately.%一般に，疲労き裂は切欠き，孔などの応力集中源かrnら発生することが多い．そのため，いくつかの代表的rnな形状の切欠きに対して，そこから発生したき裂の応rn力拡大係数が求められている．