원문정보
초록
영어
Thick-walled pressure vessel has been autofrettaged in order to improve the fatigue life of the pressure vessel. The compressive tangential residual stress near the bore of the pressure vessel due the autofrettage process is benefical to the fatigue crack initiation and propagation of the pressure vessel. However, a reverse yielding due to the Bauschinger effect during the unloading process in autofrettage causes the reduction of the compressive residual stress near the bore. In order to evaluate the fatigue crack propagation life of the autofrettaged thick-walled pressure vessel, the Bauschinger effects were considered. Stress intensity factors of the crack at the inside surface of the pressure vessel due to operating pressure loading of 707 MPa and autofrettage loading with different levels of overstrain were calculated by using finite element methods, and used for evaluating fatigue crack propagation lives. Fatigue lives of the pressure vessel with the Bauschinger effects resulted in 45% to 67% reductions in fatigue life compared to those of the pressure vessel with ideal residual stress distributions depending on the autofrettage level.
목차
1. 서론
2. 자긴가공된 압력용기이 잔류응력분포
2.1 이론적 잔류응력 분포
2.2 바우싱거 효과를 고려한 잔류응력 분포
3. 자긴가공된 압력용기 내경 균열의 응력확대계수
3.1 이상적인 잔류응력을 지닌 압력용기 내경 균열의 응력 확대계수
3.2 바우싱거 효과를 고려한 잔류응력을 지닌 압력용기 내경균열의 응력확대계수
4. 자긴가공된 두꺼운 압력용기의 피로수명 평가
4.1 이상적인 잔류응력분포를 지닌 압력용기의 피로균열전파수명
4.2 바우싱거 효과를 고려한 잔류응력분포를 지닌 압력용기의 피로균열전파수명
5. 결론
References