Sound Package Optimization For Vehicle Design Using Statistical Energy Analysis (SEA)

In this paper,an autonomous passenger car is taken as the research object to develop a cost reduction scheme under the premise of ensuring the NVH performance of the whole vehicle.Multi-scheme optimization verification is conducted through SEA simulation,and the simulation conclusion is verified through road test.According to the theory of SEA assumptions,the energy transfer theory,combined with the distribution of the vehicle structure,identifying the main sound source distribution,and to simplify the processing of vehicle accessories,we build the vehicle structure model.We build inside and outside sound field,through the theoretical calculation and experimental testing method,the parameters of the calculation model and energy transfer relationship between subsystems.We introduce the principle and test method of sound absorption coefficient and sound transmission loss.We analyzed the performance of the headliner and optimized it.Because of the inner dash thickness is uneven,so we must use the theory of biot to carry out EVA & PU material for sound transmission loss simulation,obtained the sound transmission loss of different thickness of the material.We improt in the SEA model as MNCT,matching different thickness within the innerdash.The sound package performance was imported into the SEA model,and the load application and model adjustment were completed by comparing static transfer function and dynamic interior noise,so as to verify the accuracy of the model.After SEA model is validated,we use SEA model to analyze the contribution of sound package,from the point of view of energy,sort the contribution of every sound package.To those that contribute more we should maintain its acoustic performance.To those that contribute little,we can reduce the cost of these sound package.Ensure the NVH performance of the vehicle is the premise.The SEA simple model is used to verify the effectiveness of the cavity foam block without turbulence outside the vehicle.The study shows that the cavity foam block affects the high-frequency noiseinside the vehicle,and the noise inside the vehicle is not sensitive to the thickness change of the partition.SEA method has obvious advantages in terms of quick evaluation of sound package and its contribution.It can give quantitative description of weight reduction and cost reduction and performance improvement.This method can quickly understand the changes of interior noise,which is more intuitive and convenient,Especially after the sale of automobiles.