Durability Evaluation Tests of Mold Resin for Ground Coil

The superconducting magnetically levitated transportation (Maglev) system requires ground coils suitable for long-term outdoor use along the entire length of the guideway, meaning that the assurance of stable performance and high reliability is an important consideration in developing these coils. Durability verification testing from the level of the component materials to the actual product on the assumption of commercial service is therefore necessary to guarantee total reliability. We performed flexural fatigue tests using specimens made of the epoxy resin used for actual propulsion coils. The results were used to create a fatigue limit diagram as well as a diagram to verify Miner's Law. We then confirmed the correlation between the color difference and the flexural strength by comparing the outdoor exposure test results with those of accelerated artificial exposure testing.