변후(變厚) 용접판재에서의 피로균열성장거동에 미치는 잔류응력의 영향에 관한 파괴역학적 연구(Ⅱ) = A Study on the Influence of Residual Stresses on Fatigue Crack Growth Behaviors in the Weldment Plate with Various Thickness ( Ⅱ )

다국어 초록 (Multilingual Abstract)

For the β=1 specimen with constant thickness, Crack growth rate is smoothly increasing in the a-N curve. On the other hand for β=2 specimen with various thickness, the inflection point is observed in crack growth rate near the thickness interface.
da/dN before the inflection point is increased and da/dN after the point is decreased, compared to the β=1 specimen. da/dN near the thickness interface is approached zero. The descending point was observed earlier as β increased.
Considering the relation between da/dN and λ, the crack propagation rates for the case of β=1 incrased almost linearly, however, the crack propagation rates for β=2, 3 decreased more rapidly near the thickness interface. Additionally, the decreased point in da/dN for β =3 is farther from the thickness interface than the case for β=2.