Development of Modified Creep-Fatigue Damage Model for High Temperature Life Prediction

고온 수명평가를 위한 수정 크립-피로 손상모델의 걔발

Park, Jong-Joo;Seok, Chang-Sung;Kim, Young-Jin

  • Published : 1996.11.01


For mechanical system operating at high temperature, damage due to the interaction effect of creep and fatigue plays an important role. The objective of this paper is to develop a modified creep-fatigue damage model which separately analyzes the pure creep damage for hold time and the creep-fatigue interaction damage during startup and shutdown period. The creep damage was calculated by the general creep damage equation and the creep-fatigue interaction damage was calculated by the modified equation which is based on the frequency modified strain range method with strain rate term. In order to verify the proposed model, a service of high temperature low cycle fatigue tests were performed. The test specimens were made from inconel-718 superalloy and the test parameters were wave shape and hold time. A good agreement between the predicted lives based on the proposed model and experimentally obtained ones was observed.


Linear Damage Summation Methods;Strain Range Partitioning Methods;Hold Time;Rupture Time