Abstract: With the improvement of people's quality of life, air conditioners have become indispensable necessities of life. Vibration and abnormal noise are important indicators for evaluating the quality and experience of air conditioners. Based on the resonance problem of the right side plate of the outdoor unit, the basic theory of sheet metal structural resonance is introduced. Through modal simulation analysis of its natural frequency, the reason for the beat vibration is found: the right side plate multi-order frequency enters the resonance zone and the frequency is easily excited. Superimposing with the vibration source will cause abnormal sound of beat vibration. Observing the vibration shape diagram through modal analysis, it is found that the right side plate handle and valve cover installation position, side stiffener profile and rear profile are relatively weak. By increasing the number of ribs, widening and deepening the profile, etc. The scheme optimizes the weak area of the structure, and the results show that the optimized natural frequency effectively avoids the working frequency of the vibration source, solves the resonance problem, and improves the sound quality of the outdoor unit of the air conditioner.

Key words: Right side plate, Mode, Natural frequency, Mode shape