Research and Analysis on Tensile and Compressive Fatigue Performance of Cryogenic Axial Insulation Breaks

The composite axial insulation breaks (IBs) are key components of the supercon- ducting magnet system for the international thermonuclear experimental reactor (ITER). In order to ensure the safe operation of the IBs during the 20 year lifespan of ITER devices, tensile and compressive fatigue tests were conducted by simulating actual working conditions and optimizing the test programs. The IBs were evaluated by testing their helium tightness after mechanical fatigue tests. In addition, fatigue analysis was performed using ANSYS software and an experi- mental S-N curve. The test data showed that the maximum helium leakage rate was less than 1.0x10^-9 Pa·m³ /s, which met the design requirements of the ITER IBs. ANSYS analysis results are also consistent with the test results from the theoretical viewpoint.