Dynamic Analysis Of The Heavy-Duty Truck Cab

Owing to the fact that the developing international markets of home-made heavy truck has resulted in fierce competitions, what demand on the performance of heavy truck is not only the load capacity and power property, but also the comfortability and low noise. Thus, in order to reduce the vibration and noise, the dynamic property of cab should be studied deeply. According to this, the dynamic property and acoustic field of a type of truck cab are studied using FEM method.3D model of the heavy-duty truck cab was established by UG, and then was imported into HyperMesh for FEA preprocessing and meshing. Finally, the exported modal file was calculated by ANSYS and the fist 10 modal frequency and mode shape was gained; it is found that the fist modal frequency was slight higher than the idle frequency. Otherwise, the weak parts of the structure can be discovered though the mode shape analysis and the response of them can be obtained through truck cab harmonic analysis and transient analysis. The calculated results show that the maximum vibration amplitudes of the response lied on the lower parts of front wall window and side wall window, and these parts are liable to fatigue failure. Second, the acoustic field in the cab is calculated using SYSNOISE. According to the results, the modal of the acoustic field shows a symmetrical distribution along front-back, left-right, up-down directions, and the resonance frequency and model shape is determined mainly by its geometrical property. In order to further analysis the radiation noise pressure in the cab, the acoustic-structure coupling calculation is presented, and the acoustic pressure level curve at the ears of the driver and passengers is obtained.Finally, the weak parts of the cab, such as side wall window, rear wall window and roof, are stiffened using reinforcing plates according to the dynamic property analysis of the cab. However, the structure modal and acoustic pressures at the ears of the stiffened cab are calculated, which turns out that the stiffened process could help to improve the lower modal and reduce the noise of the cab.