Optimization design of dynamic vibration absorbers for vibration and noise reduction of composite fairing

The sound insulation design of the fairing on rockets is important for the model selection, tests and safe operation of the internal equipment. To improve the vibro-acoustic environment and the sound insulation performance of the fairing, we first conduct the equivalent mechanical modelling of the composite fairing. Then, based on the basis changes, the dimension reduction method is proposed in the modal space to optimize the Dynamic Vibration Absorber (DVA) by considering the coupled modes. Finally, the optimization design for the location and material parameters of dynamic vibration absorbers is performed based on the equivalent mechanical modelling of the fairing. Numerical simulations are conducted on a composite fairing to verify the proposed method. Results of the fairing with a total mass of 1 177.3 kg show that under the constraint of the additional mass, the Root Mean Square (RMS) value of the sound power level in the frequency band 0-100 Hz is reduced from 254.8 dB to 238.8 dB after the addition of the dynamic vibration absorbers with a total mass of 14.6 kg. The vibration and noise level in the designed frequency band is significantly reduced and the vibro-acoustic environment is improved. © 2022, Beihang University Aerospace Knowledge Press. All right reserved.