Bus Bodywork Vibration And Coupling Analysis Of Interior Sound Field

The characteristic of vibration and noise of an automobile has become an important guide line to evaluate an automobile during the development of manufacturing and comfort of automobiles. The researched object in this study is one kind of buses, and we research for the dynamic characteristic of the automobile’s configuration and the coupling sound field inside the automobile by finitude element method and boundary element method.First, this thesis introduced the developing status of the noise inside automobiles, engendering mechanism and transmitting approaches of vibration and noise, and noise estimative criterion.Second, it built models of the bus in different ways and analyzed these models on the basis of finite element modeling method, and obtained the most effective way to build the bus model.Third, it systemically researched the configuration characteristic of the bodywork, acoustic characteristics of compartment cavity sound field inside the bus, coupling systemic characteristic between bodywork’s configuration and acoustic characteristics of compartment cavity sound field inside the bus by the finitude element software ANSYS and SYSNOISE. The configuration modes of the bodywork and the acoustics modes of the bodywork were analyzed. The modes of the bodywork’s configuration can exhibit vibration transference and noise generation. These findings are helpful to offer guidance for noise forecast, noise cause diagnosis, and analyze the acoustic contribution of the wainscot.Then, it calculated the harmonic response of the bodywork and acoustic characteristics of compartment cavity sound field inside the bodywork which are bestirred by the motor, and get the curves of acoustic pressure to forecast the noise inside the automobile.Last, the boundary element method was used to build the boundary element model of compartment cavity sound field of the bodywork. It also calculated acoustic sensitivity of floor board and ceiling of the bodywork, and found the sensitive frequency by the sensitivity method. The findings may give instruction for the design of the bodywork.