Abstract: Vacuum arc skull furnace is a special material casting equipment. In the process of centrifugal casting, it may be affected by periodic excitation force and vibration of external equipment, which will induce resonance of its own shell. In consequence, shell resonancereduces the casting quality and formssecurity risk. In this paper, the modal analysis of avacuum arc furnace is carried out, and it is found that the local design deficiency is the cause of the low-order local mode. By reinforcing the structure, the first-order mode frequency is increased from 56.786Hz (close to the power frequency) to 77.610Hz(relatively safe), and the amplitude is reduced from 3.540mm to 0.323mm. In conclusion, modal shape optimization method has achieved a good effect of vibration reduction design.

Key words: vacuum arc furnace, modal analysis, mode optimization, vibration control, vibration reduction design