敷设粘弹性层舱室的振动特性仿真分析与试验

Simulation analysis and experiment on vibration characteristics of cabin with viscoelastic layer

轮船舱室的减振设计需要对舱室的固有振动特性和响应进行分析。基于Ansys Workbench对舱室进行模态分析,利用壳单元对舱室进行建模,获得其前20阶的固有频率、振型,并对仿真结果和试验结果进行对比。利用半功率带宽法测出舱室阻尼比,在模态分析基础上对舱室进行谐响应分析,得到位移和频率响应曲线。考虑粘弹性材料频变特性,对敷设粘弹性层舱室进行谐响应分析。研究结果表明,舱室的模态仿真结果和试验测试的结果吻合良好,误差均在6%以内,试验验证了模型和计算方法的正确性。舱室的位移幅值在28 Hz时振幅最大,即模态阶数的第2阶为舱室易发生共振时的频率,从而为舱室的设计和优化提供了有效参考。敷设粘弹性层后舱室振动响应降低了19.6%,验证了该粘弹性阻尼材料能够有效抑制在基础激励下的振动响应。

The natural vibration characteristics and response of the cabin need to be analyzed during the vibration reduction design.In this paper,modal analysis of the cabin is carried out based on Ansys Workbench platform,and the cabin model is established by shell elements.The natural frequencies and vibration modes of the first 20 orders are obtained,and the simulation results are compared with the experimental results.The damping ratio of the cabin is obtained by the half power bandwidth method.On the basis of modal analysis,the harmonic response of the cabin is analyzed,and the displacement and frequency response curves are obtained.The harmonic response of the cabin with viscoelastic layer is analyzed considering the frequency-dependent characteristics of viscoelastic material.The results show that the modal simulation results are basically consistent with the test results,and the errors are within 6%.The accuracy of the model and caculation method are verified.The displacement amplitude of the cabin is maximum at 28 Hz,that is,the second-order natural frequency is the frequency when the cabin is prone to resonance,which provides an effective reference for the design and optimization of the cabin.The vibration response of the cabin with viscoelastic layer is reduced by 19.6%,which verifies that the viscoelastic damping can effectively suppress the vibration response.