Vibratory Stress Relief in Manufacturing the Rails of a Maglev System

To reduce the welding induced residual stress in the rails of a magnetic levitation (maglev) transport system, the procedure of vibratory stress relief (VSR) is applied and discussed in this paper. Suitable welding sequence for the rails is introduced to keep the residual stress low. Qualitative analysis with scanning curve shows that the peak of acceleration becomes higher after the procedure of VSR and the resonant frequency becomes lower. It means that the procedure of VSR is effective according to the JB/T5926-91 standard. The residual stress in the rail was measured before VSR and after VSR, using hole-drilling method, and the result shows that the average principal stresses was reduced by about 30% after VSR.