회전원판 내에 존재하는 균열에 대한 응력확대계수

Abstract

회전원판 내에 존재하는 균열에 대한 응력확대계수를 J 적분과 유한요소법을 이용하여 구하였다. 회전으로 인한 원심력이 존재하기 때문에 J 적분식을 다소 수정하였다. 요소의 원심력은 각 node에 고르게 나누어 각 node에서의 반경방향으로 가하였다. 균열길이가 같은 경우 원판 밖으로 터진 균열에 내한 응력확대계수가 원판 내에 갇힌 균열의 두 배가량이었다. 원판 내에 갇힌 균열의 경우 원판의 중심에서 가까운 균열선단에 대한 응력확대계수가 중심에서 먼 균열선단보다 높았다.

The stress intensity factors for a crack in a rotating disk were calculated using the concept of J-integral and the finite element method. J-integral formula was modified in consideration of the presence of a centrifugal force due to rotation. The centrifugal force of an element was divided equally and applied in a radial direction at each node of the triangular element. The stress intensity factor for an edge crack is always larger than that for an internal crack of the same crack length and the maximum ratio reaches about two. For an internal crack with two crack tips the stress intensity factor at inner crack tip is always larger than that at outer crack tip.

The stress intensity factors for a crack in a rotating disk were calculated using the concept of J-integral and the finite element method. J-integral formula was modified in consideration of the presence of a centrifugal force due to rotation. The centrifugal force of an element was divided equally and applied in a radial direction at each node of the triangular element. The stress intensity factor for an edge crack is always larger than that for an internal crack of the same crack length and the maximum ratio reaches about two. For an internal crack with two crack tips the stress intensity factor at inner crack tip is always larger than that at outer crack tip.