301 / 2021-04-22 17:03:24

Vibration Reduction Effects of Multi-layered Noise Absorbing and Insulating Materials

Multi-layered structure,Absorbing and insulating materials,Vibro-acoustic model,Multi-layered Structure,Finite element method

Multi-layered structure of noise absorbing and insulating materials are wildly used as passive noise control treatment in the vehicle. For noise and vibration attenuation, they are usually attached to the cabin panels, which is characterized by significant structure vibration and radiate sound into the vehicle. In this work, the effects of multiple-layer structure with absorbing material and insulating materials on vibration reduction performance is discussed. A simplified numerical method is proposed for predicting the vibration reduction effects of single or multiple layers of porous materials (polyester felt type) with one layer of EPDM insulating materials. For quantifying the vibration reduction effects and identifying the simulation parameters, transmissibility and vibration damped frequency bands are observed by the results of excitation experiments. Multi-layered absorbing and insulating materials are also attached to the bottom plate of an acoustic box, which is designed as a simplified experimental model of the vehicle cabin. The reductions of system response amplitude are compared by the results of hammer excitation experiment and numerical simulation. It shows that the simulation results are in good agreement with the experiment results.