Fatigue life prediction of continuous glass-fiber reinforced elium thermoplastic composites via energy based thermographic approach

The long-term performance of composite materials produced within the scope of lightweighting, should be examined with fatigue tests. Nonetheless, these tests take a long time and require a lot of energy. For overcoming these limitations, the thermographic method was used during the fatigue test and recorded temperature changes. Before starting the fatigue tests, the mechanical properties of glass fiber-reinforced Elium-based composites were clarified via tensile and three-point bending tests for two different fiber orientations (0/90 and 0/90/45). Then, the fatigue tests were carried out to identify the long-term performance of these materials. During the test, temperature values were recorded with an infrared camera. These values were converted to energy dissipated per cycle and temperature increase. These data established high cycle fatigue strength limits for both fiber orientations. In addition, using the fatigue test data, the potential cycles at lower stress values were calculated using a mathematical model and were validated with verification tests. With this method, the fatigue cycle has been predicted for high cycle fatigue tests and it carried out the validation test successfully with 93% similarity of fatigue cycle. Finally, the cycle numbers of all low-stress high-cycle fatigue tests were determined.