Analysis And Optimization Of Engine Mounting System Based On Transfer Path Analysis

Vibration noise is one of the vehicle performance indexes of consumer concern which reflecting the manufacturing level of automobile while it is also one of the diversified competition technical indexes in automobile market.Excessive interior vibration noise not only has impact on driver’s mood,obstructing the communication between passengers,but also cause sever fatigue to driver endangering traffic safety sometimes.As for these,controlling vehicle interior noise more effectively is the key aspect during research and development stage of automobile making which manufacturers must pay high attention to.Most of all,the mounting system is the key link to reducing vibration and noise.Therefore,how to analyze and evaluate the influence of mounting system to interior noise has significant meaning in the reducing of vibration and noise.This paper,based on a mini car,through transfer path analysis,identify the major sources of interior noise and optimize the engine mounting system from the point of noise suppression.First of all,conducting full throttle acceleration test on running drum tester and based on the transfer path of vibration energy from engine to drive’s right ear,the vehicle interior noise transfer analysis model based on transfer path analysis is built and corrected by using partial coherence analysis.Predicting the interior noise by putting the measured data into the analysis model and contrasting the predict results and test results,the analysis model is proved to be accurate.Analyzing transfer characteristic of each transfer path through path transfer function,mount transfer function and frequency contribution,major transfer path and subsystems are identified which pointing out the adjustment direction in reducing interior noise.Based on ADAMS software platform,a parametric and dynamic model for mounting system is established.Combined with dynamic simulation,vehicle interior noise is obtained.From mounting stiffness analysis,mounting install angle analysis,the level and effect of influence of the parameters of mounting system on vehicle interior noise are discussed.With the optimization objective of the lowest interior noise,the stiffness of mounting system are optimized,which based on interior noise transfer analysis model.These can provide reference significance for design of powertrain mounting system from the point of noise suppression.