Noise Study Of Bulldozer Cab Based On Acoustic-structure Coupling

With the increasing prosperity of the construction machinery market and the increasingly fierce competition,the noise level of the construction machinery has been more stringent requirements.For the widely used bulldozers,all kinds of vibration in the operation will eventually pass through the frame to the cab and the external noise by air media to transfer to the cab,resulting in cab noise is particularly large,serious impact on the driver's acoustic comfort,can easily lead to fatigue and discomfort caused by the wrong judgment even accident.Therefore,it is important to improve the acoustic environment of the bulldozer cab and to reduce the noise level in the cab,both in terms of economic value and social benefits.In this paper,a bulldozer cab is taken as the object of study.The main research contents are as follows:1.By using the Hypermesh finite element analysis software to three-dimensional structure has been built and simplified mesh,using Optistruct solver for structural modal analysis of the cab;then by applying harmonic load chamber on the finite element model of bulldozer driving,harmonic response analysis of the response results using the displacement to observe and analyze the vibration condition the cab of the whole.2.By the Hypermesh software will be driving the air inside the chamber surrounded by the part extracted form cavity grid,by solving the tune free modal to determine whether the cab can occur within the cavity resonance phenomenon;then in the LMS.Virtual.lab software to create a sound solid coupling system model and the acoustic solid coupling modal simulation,the acoustic properties of the cavity and the actual vibration and noise coupling.3.To set up before the acoustic solid coupling system by adding harmonic load to the frequency response analysis,in accordance with the peak pressure pressure curve in the frequency to judge the impact of specific frequency sound pressure cavity size.At the end of the cab acoustic solid coupling model was used to analyze the acoustic contribution of plate,and then according to the analysis result of plate contribution,the contribution of the cab noise is relatively large amount of the plate of thickness optimization.