The Noise Evaluation And Control Of Vibration Of DF_4D Diesel Cab

This article chooses the dalian locomotive overlook DF4D diesel as the research object, on the front cab from mechanical noise level of diesel engine and wheel/rail assessment and prediction, and a certain amount of noise and vibration control method is put forward.On the processing of noise source, this paper mainly considers the power installation of16V240diesel engine and wheel/rail contact collision on the chassis of a driver chamber and the influence of the solid noise. And simplifies complex vibration force into the strong point on the unit of three degrees of freedom, save a lot of mechanics analysis work, convenient analysis of the noise characteristic of the cab, in view of the noise type study, to simplify the vehicle structure model for the corresponding processing, only keep the room to the driver a solid noise transmission way-both ends of the detailed structure of the chassis and the driver the stiffened plate structure of the interior ministry and skin.Specific technical route is:application of Pro/E3d modeling of white body, and using Hypermesh discrete grid, the grid size meet the requirements of the acoustic frequency calculation in ANSYS lanczos method was applied to extract the former structure modal of400hz, and combined with the driver chamber cavity acoustic modal coupling modal analysis of acoustic finite element method, the application in the LMS-virtual sound based on the fluid-solid coupling modal to the driver room sound field simulation calculation, respectively200hz in front of the diesel engine and wheel/rail by the driver of room sound field response, and sound pressure level driver’s right ear response curve.Combination of three kinds of modal calculation results and the cab vibration response analysis based on two kinds of incentive of multiple peak sound pressure level. Results show that the causes of the driver chamber pressure peak basically has two kinds, one is the structure of the coupling mode is triggered, under the condition of the structure of the strong resonance, produce intense pressure peak value; Another is due to the structure of wall plate and cavity fluid coupling action led to a strong acoustic resonance, which under the condition of the smaller structure vibration produced relatively large pressure peak.For the reasons of the peak certain vibration noise reduction plan, analysis result also to have certain practical reference value.