報告題目：Rapid determination of fatigue property for CFRP laminates based on infrared thermographic method
We proposed three new treatment methods in terms of relation curve between experimental temperature response and the applied stress amplitude so as to determine the fatigue limit with uniqueness. Those three methods were all evaluated by applying to the experimental data from literature and the error of results were discussed and analyzed. In addition, numerical experiments were carried out to investigate the influence of loading stepped length and random error on each new treatment method.
A new fatigue life prediction model combining temperature variation and damage accumulation is proposed. A mechanical stiffness degradation model is developed to characterize damage index. First, the improved thermographic method is used to determine fatigue limit based on the data of stabilized temperature rising. Following this, a two-parameter function are used to fit the normalized stiffness degradation data. Then, the normalized failure threshold stiffness can be calculated and by setting damage index, the whole S-N curve can be determined. Both experimental data from literature and new fatigue testing of unidirectional CFRP laminates are used to verify the new proposed model.