The Damping Materials Optimization Research Of Body Floor

Inside low-frequency vibration and noise are the main sources affecting comfortability.These vibration and noise are mainly from the vibration of the thin plate of radiation.Damping materials on the surface of the thin plate is one solution to improve damping properties of the composite structure,reduce the panel structure size of the radiated noise.However,due to the complex body panel structure additional damping materials are applied,mostly on the basis of engineering experience with low efficiency.The selection and arrangement of body damping structure optimization is important for noise and vibration reducing.Based on an enterprise project,the research on the selection and optimizing arrangement of viscoelastic damping material was conducted to reduce vibration and noise inside the vehicle.The main work of this paper was as follows.1)The modeling method of viscoelastic damping material and layout optimization methods and the characterization method of damping performance of viscoelastic damping materials were introduced.Factors affecting damping characteristics of viscoelastic damping materials was analyzed,in which the main focus was put on the influence of temperature and frequency on the performance of viscoelastic damping materials.2)Comparison of original damping material and several different viscoelastic damping materials on the loss factor along with temperature and frequency were done based on DMA dynamic viscoelastic damping materials and spectrum analyzer.Then,the original damping material and one material with bigger loss factor(Dy-1)were applied to the car floor.Interior noise test showed that,the(Dy-1)material had better performance on noise reduction.Thus,the(Dy-1)material was selected in this research.3)The finite element model of the white body was established,and the model was evaluated.The simulation modal result was compared with test data,which verified the correction of the FEM model.4)On the basis of the material and body FEM analysis,optimization on the damping material arrangement on car body were done by topological optimization method and comprehensive method of strain energy.Topology optimization was conducted on the tenth order modal loss of body floor,which can use 60% damping material arrange area to achieve the same loss factor as full coverage of damping material.While,the strain energy method results showed that only 40% of damping material arrangement can get the same noise reduction performance as original full coverage.