유한요소법에 의한 박판의 크리프 수명예측에 관한 연구

Abstract

In order to predict the creep life of the sheet, the small punch creep process is analyzed by the finite element method to obtain the value of equivalent stress in the area of stress concentration. The equivalent stress in the secondary curve of the creep is equal to the stress in the uniaxial creep test. The creep life of the sheet can be then predicted by both the relationship between the small punch creep test load and the uniaxial creep test stress and the LMP which shows the rupture time in terms of the temperature and stress. In this study, the small punch creep process was simulated by using elastoplastic and creep finite element analysis. The deflection curve of the punch by FEM was compared with that the experiment to get the friction coefficient and specimen size of the model to be used in the simulation. Applying assessment to the 9Cr1MoVNb sheet, its creep life in terms of LMP was evaluated. The creep life studied in this research was verified by comparing with the LMPs of the previous study and uniaxial creep test