Abstract Based on the continuum damage mechanics, a new damage model has been developed for fatigue-creep interaction in this paper. This model researched the damage of fatigue, creep and their interaction respectively. In order to apply this model to the practical engineering condition, fatigue-creep interaction experiments have been carried out to research the damage evolution. These tests are conducted at 540℃ under stress control, using a trapezium waveform with the hold-time per cycle. Cylindrical specimens of 1.25Cr0.5Mo steel were used in the fatigue-creep interaction experiments. According to the experiments, the changing rule of mean strain has been studied in this paper. Defining the change of mean strain as the damage variable, damage curves of different stress ranges have been obtained based on the damage model the above damage model. Results showed that the values of damage calculated from the damage variable definition mentioned above were in good agreement with these damage curves. Besides, based on the damage model and the change rules of mean strain, this paper also discusses the failure assessment in engineering. A method to prevent the rupture of engineering components has been proposed in this paper.
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