316L 스테인리스강의 상온 반복 거동에 대한 수정 다층 모델의 적용성 검토

Abstract

The validity of modified overlay model to describe the cyclic behavior of annealed 316L stainless steel at room temperature was investigated. Material parameters(~fi, mib, η, E) fur the model were obtained through constant strain amplitude test. The strain amplitude dependency of elastic limit and cyclic hardening, which were the characteristics of this model, were considered. Eight subelements were used to describe the nonlinearity of the hysteresis loops. The calculated hysteresis curve in each condition (0.5％, 0.7％, 0.9％ train amplitude test) was very close to the experimental one. Two tests, incremental step test and 5-step test, ere performed to check the validity of modified overlay model. The elastic limit was saturated to the one of the highest strain amplitudes of the block in the incremental step test, so it seemed to be Masing material at the stabilized block. Cyclic hardening was successfully described in the increasing sequence of the strain amplitude in 5-step test. But, the slight cyclic softening followed by higher strain amplitude would not be able to simulate bymodified overlay model. However, the discrepancy induced was very small between the calculated hystereses and the experimental ones. In conclusion,Modified overlay modelwas proved to be appropriate in strain range of 0.35％~ 1.0％..0％.