抄録
In recent years, in order to establish a guideline for liquefied hydrogen storage tanks, a study on the evaluation technique of material integrity under cryogenic environment has been carried out. However, fracture toughness evaluation with plastic strain at cryogenic temperature is still an important issue in design. Until now, the estimation of the generated stress and the confirmation of its validity have been carried out for the trial design tank. In order to establish the guideline, in addition to the limited condition of the trial design tank, the soundness evaluation under the severest condition assumed in the design is required. This paper presents a simplified method for estimating the J-integral value using reference stress, aimed at evaluating fracture behavior under design limit conditions. The applicability of the proposed method to cryogenic materials was verified. Furthermore, the J-integral values under the design limit conditions of the storage tank were estimated using this approach.