FEM Modal Analysis And NVH Performance Research Of Heavy-duty Truck

With the increasingly fierce competition in heavy-duty truck market, the performance ofNVH has attracted an intense attention among car companies. Besides power performance andfuel economy, more and more individuals have also taken a fancy to ride comfort. In thispaper, a finite element partition process is established for a certain type of heavy-duty trucksin China. According to the process, the body in white model and the trimmed body finiteelement model of the cab are established. Then, the cab modal of body in white and trimmedbody is separately analyzed by modal analysis and modal test, and the comparativeverification of the two modal results is undertaken as well. Finally, based on the trimmedbody finite element model of the cab, the NVH performance of the cab is improved.1. In finite element modeling, Hypermesh is introduced to generate the body in white caband trimmed body cab mesh in this paper. Then, a mesh process including trimmed body cabis set up, and modeling methods of glass strip and damping rubber sheet are proposed.2. In modal analysis of the cab, the body in white model and the trimmed body model ofthe cab are analyzed through two ways: a way that gets the modality of the cab withRADIOSS based on finite element model analysis method; a way that gets the modality of thecab with modal test system based on the tests, which reflects the vibration characteristics ofthe cab.3. In the comparative verification of simulation and tests, firstly, the simulation and testscomparison of the origin dynamic rigidity of the body in white are carried on, which verifiesthat the body in white modal meets the subsequent requirements basically. Then, thecorrelation of the modal simulation and experiment results is analyzed with Virtual. Lab,which verifies that the finite element model is right.4. In NVH performance improvement, based on the trimmed body cab, Noise TransferFunction (NTF) for the cab is analyzed with Virtual. Lab Acoustics in viscose state and non-viscose state, which indicates that viscose state makes for the reduction of cab sound pressureexcept for certain frequencies. So, sticking the damping materials to the region of theexcessive vibration amplitude is put forward.Through the study above, the introduction of simulation to vehicle research and design provides the improvement direction for vehicle design, shortens the design cycle, saves thedesign cost.