Modal Structural Analysis for Frame of a Heavy Truck

Modal finite element analysis(FEA)is an effective mean for identifying the dynamic performance of vehicle structure.A FEA modal analysis model based on shell elements was built for obtaining the dynamic characteristics of the structure of a heavy truck frame.Modal parameters of the frame under free conditions were obtained from the modal analysis using FEA Software NASTRAN.Meanwhile,the excitation caused by the unbalance of the wheel and drive shaft was analyzed.The structure dynamic performance of the frame was evaluated.The results showed that the exciting frequency caused by the unbalance of the wheel and drive shaft under different speed was closed to the first torsional vibration frequency,double frequency,the firsttransverse bending torsional vibration frequency and the 11th to 18th vibration frequency of the frame,which caused the of the frame.The research provided reference for the further improvement of frame structure.