基于磁流变弹性体的推进轴系半主动式吸振器研究

Semi-active dynamic absorber of a ship propulsion shafting based on MREs

根据船舶推进轴系纵振动力学特性,针对动力吸振器的减振机理进行研究,并对半主动式吸振器的设计参数影响规律进行理论分析。基于磁流变弹性体的剪切模量可由外加磁场控制的特性,设计了一种剪切刚度可调的半主动式吸振器,对其移频特性进行了试验测试,并在1∶4的船舶轴系缩比模型上进行了变转速工况下吸振效果试验。实验结果表明,该吸振器具有12.3 Hz的移频范围,移频特性曲线线性度良好;并且在不同转速下相比被动式吸振器均有更好的吸振效果,进一步验证了利用磁流变弹性体设计推进轴系半主动式吸振器的可行性。

According to longitudinal vibration characteristics of a marine propulsion shafting, the vibration reduction mechanism of dynamic absorbers was studied. The influences of semi-active dynamic absorbers, parameters on their vibration reduction effect were analyzed. Magneto-rheological elastomer （ MRE） was a kind of smart materials, its shear modulus could be controlled by an external magnetic field. Based on this property, a semi-active dynamic absorber with adjustable stiffness was designed. Its natural frequency-shifting feature was tested. Furthermore, The vibration reduction effect tests for a model of a ship propulsion shafting with a scale ratio of 1 ？ 4 and MREs-based SDA under the condition of varying rotating speed were conducted. The results showed that the designed MREs-based SDA has a natural frequency-shifting range of 12. 3 Hz, its natural frequency-shifting feature curve has a good linearity; it has a better vibration energy absorption capacity than classic passive dynamic absorbers do under different rotating speeds; the feasibility of using MREs to design semi-active dynamic absorbers for a ship propulsion shafting is verified.