전차선의 수명을 기초로 한 압상력 상한에 관한 검토

초록

French supplier for the KTX high speed catenary system established 200N as a upper limit for uplift forces when a train speed was 300km/h. We reviewed the validity of a upper limit for the uplift forces in terms of fatigue life. First of all, bending stresses of a contact wire were calculated using a closed form of formula derived by Japanese railway researchers before. Bending stresses of the wire depend largely on both uplift forces and a ratio of train speed to wave propagation speed. Substituting KTX design parameters into the formula brought us bending stresses below a fatigue limit. We think that 200N is acceptable as a upper limit of uplift forces. However, if a train speed increases to 350km/h, 200N is unacceptable because bending stresses exceed the fatigue limit. Therefore, a train speed should be taken into account when determining a upper limit for uplift forces on the contact wire in railway.