复合材料整流罩减振降噪的动力吸振器设计

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

运载火箭整流罩的隔声性能设计对内部设备的选型、试验和安全运行至关重要。为改善整流罩内低频声振环境,提高整流罩低频段隔声性能,首先,针对复合材料整流罩结构开展力学等效建模;其次,提出一种基于基变换模态空间内降维理论,解决了考虑多模态耦合的动力吸振器(DVA)设计问题;最后,基于整流罩等效力学模型开展了动力吸振器位置及材料参数的优化设计。针对某型复合材料整流罩开展仿真研究,验证新方法的有效性。结果表明:针对某型质量为1 177.3 kg的整流罩模型,添加总质量为14.6 kg的动力吸振器之后,0~100 Hz频段内声功率级均方根(RMS)值从254.8 dB降至238.8 dB,设计频段内声振响应被有效控制,声振环境得到改善。

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.