Safety analysis on liquefied tank with defect of hydrogen blistering using Abaqus

A J-integral based method is proposed to assess the safety of the liquefied tank with defects of hydrogen blistering. First, measuring tools, magnetic inspection powder and an ultrasonic thickness gauge are used to defect the type, position and morphology. Then Abaqus software is adopted to analyze the deformation and stress distribution, and calculate J-integral value of crack tip through definition (JA) and stress intensity factor (JK). Finally, the J-integrals calculated are compared with a critical value for the material to predict fracture and assess the safety. The results show that the J-integral value by JK is about 155% greater than that by JA when the pressure in hydrogen blistering is 5 MPa, and about 10% greater than that by JA when the pressure in hydrogen blistering is 3 MPa or 1 MPa. It seems that the value calculated by JK will be overestimated for the safety assessment. The safety assessment results by JA indicate that the hydrogen blistering defect with cracks is likely to propagate when the pressure in hydrogen blistering increases to 3 MPa.